diff --git a/internal/cloud/server-code-agent-http.ts b/internal/cloud/server-code-agent-http.ts
index 99ff851e..b29472cc 100644
--- a/internal/cloud/server-code-agent-http.ts
+++ b/internal/cloud/server-code-agent-http.ts
@@ -1162,7 +1162,7 @@ export async function handleCodeAgentChatResultHttp(request, response, url, opti
     return;
   }
   if (context.found) {
-    const body = codeAgentTurnStatusPayload({ traceId, result, snapshot: context.trace, resultPollError: null, refreshError: null, options });
+    const body = codeAgentTurnStatusPayload({ traceId, result, snapshot: context.trace, resultPollError: null, refreshError: context.refreshError ?? null, options });
     sendJson(response, body.terminal === true ? 200 : 202, codeAgentCompatProjectionPayload({
       accepted: body.ok,
       shortConnection: true,
@@ -1214,7 +1214,7 @@ async function resolveCodeAgentTurnStatusSnapshot(traceId, options) {
     result: context.result,
     snapshot: context.trace,
     resultPollError: null,
-    refreshError: null,
+    refreshError: context.refreshError ?? null,
     options
   }));
   return { statusCode: body.ok ? 200 : 404, body: codeAgentCompatProjectionPayload(body, context) };
@@ -1330,11 +1330,12 @@ async function readCodeAgentCompatProjection(traceId, options = {}) {
   const projectionTrace = await readModel.traceSnapshot(traceId);
   let trace = traceSnapshotWithTerminalEvidence(projectionTrace, result, traceId, null);
   const refreshed = await refreshAgentRunProjectionForCompatRead({ traceId, result, trace, options });
+  if (refreshed.runnerTrace) trace = traceSnapshotWithTerminalEvidence(refreshed.runnerTrace, result, traceId, refreshed.refreshError ?? null);
   if (refreshed.result && refreshed.result !== result) {
     result = refreshed.result;
     trace = traceSnapshotWithTerminalEvidence(refreshed.runnerTrace ?? trace, result, traceId, refreshed.refreshError ?? null);
   }
-  const projection = readModel.projectionDiagnostics({ traceId, result, trace });
+  const projection = readModel.projectionDiagnostics({ traceId, result, trace, refreshError: refreshed.refreshError ?? null });
   const found = Boolean(result || session || (trace && trace.status !== "missing") || trace?.persisted === true);
   return { result, session, trace, projection, found, refreshError: refreshed.refreshError ?? null };
 }
@@ -1366,9 +1367,11 @@ function codeAgentCompatProjectionPayload(payload = {}, context = {}) {
     ...payload,
     projection,
     projectionStatus: projection.projectionStatus ?? null,
+    projectionHealth: projection.projectionHealth ?? null,
     lastProjectedSeq: projection.lastProjectedSeq ?? null,
     sourceRunId: projection.sourceRunId ?? null,
     sourceCommandId: projection.sourceCommandId ?? null,
+    staleMs: projection.staleMs ?? null,
     blocker: projection.blocker ?? null,
     workbench: traceId ? {
       turnUrl: `/v1/workbench/turns/${encodeURIComponent(traceId)}`,
diff --git a/internal/cloud/server-workbench-http.test.ts b/internal/cloud/server-workbench-http.test.ts
index 145ffdc3..c771cd1c 100644
--- a/internal/cloud/server-workbench-http.test.ts
+++ b/internal/cloud/server-workbench-http.test.ts
@@ -7,9 +7,35 @@ import { test } from "bun:test";
 import { createCloudApiServer } from "./server.ts";
 import { createCodeAgentTraceStore } from "./code-agent-trace-store.ts";
 import { createCodeAgentChatResultStore } from "./server-code-agent-http.ts";
+import { createWorkbenchTurnProjection, projectionDiagnostics } from "./workbench-turn-projection.ts";
 
 const ACTOR = { id: "usr_workbench_reader", username: "reader", displayName: "Reader", role: "user", status: "active" };
 
+test("workbench projection diagnostics exposes AgentRun refresh errors without terminal inference", () => {
+  const traceId = "trc_projection_refresh_degraded";
+  const result = {
+    traceId,
+    status: "running",
+    agentRun: { runId: "run_projection_refresh_degraded", commandId: "cmd_projection_refresh_degraded", status: "running" }
+  };
+  const trace = { traceId, status: "running", events: [], eventCount: 0, updatedAt: "2026-06-18T01:00:00.000Z" };
+  const projection = createWorkbenchTurnProjection({ traceId, result, trace });
+  const diagnostics = projectionDiagnostics({
+    traceId,
+    result,
+    trace,
+    projection,
+    refreshError: { code: "agentrun_result_timeout", message: "状态更新超时，AgentRun 结果暂不可见。", retryable: true, timeoutMs: 2500 }
+  });
+  assert.equal(projection.status, "running");
+  assert.equal(diagnostics.projectionStatus, "blocked");
+  assert.equal(diagnostics.projectionHealth, "degraded");
+  assert.equal(diagnostics.blocker.code, "agentrun_result_timeout");
+  assert.equal(diagnostics.blocker.message, "状态更新超时，AgentRun 结果暂不可见。");
+  assert.equal(diagnostics.sourceRunId, "run_projection_refresh_degraded");
+  assert.equal(diagnostics.sourceCommandId, "cmd_projection_refresh_degraded");
+});
+
 test("workbench read model exposes session, messages, turn, and trace without write repair", async () => {
   const traceStore = createCodeAgentTraceStore();
   const results = createCodeAgentChatResultStore();
@@ -751,6 +777,71 @@ test("workbench realtime stream accepts session authority without project or wor
   }
 });
 
+test("workbench read model exposes runtime trace projection query failures as projection blockers", async () => {
+  const traceStore = createCodeAgentTraceStore();
+  const results = createCodeAgentChatResultStore();
+  const traceId = "trc_workbench_projection_store_unavailable";
+  const session = {
+    id: "ses_workbench_projection_store_unavailable",
+    projectId: "prj_hwpod_workbench",
+    agentId: "hwlab-code-agent",
+    status: "running",
+    ownerUserId: ACTOR.id,
+    conversationId: "cnv_workbench_projection_store_unavailable",
+    threadId: "thread-workbench-projection-store-unavailable",
+    lastTraceId: traceId,
+    updatedAt: "2026-06-18T01:10:00.000Z",
+    session: {
+      sessionStatus: "running",
+      lastTraceId: traceId,
+      messages: [
+        { role: "user", text: "projection store unavailable", traceId, status: "sent", createdAt: "2026-06-18T01:09:58.000Z" },
+        { role: "agent", text: "", traceId, status: "running", createdAt: "2026-06-18T01:09:59.000Z" }
+      ],
+      valuesRedacted: true,
+      secretMaterialStored: false
+    }
+  };
+  traceStore.append(traceId, { seq: 1, type: "backend", status: "running", label: "runner:created", terminal: false, createdAt: "2026-06-18T01:10:00.000Z" });
+  results.set(traceId, { status: "running", traceId, ownerUserId: ACTOR.id, sessionId: session.id, threadId: session.threadId });
+  const accessController = {
+    store: {
+      async getAgentSession(sessionId) { return sessionId === session.id ? session : null; },
+      async getAgentSessionByTraceId(requestTraceId) { return requestTraceId === traceId ? session : null; }
+    },
+    async ensureBootstrap() {},
+    async authenticate() { return { ok: true, actor: ACTOR, session: { id: "uss_workbench_reader" } }; }
+  };
+  const runtimeStore = {
+    async queryAgentTraceEvents() {
+      const error = new Error("runtime query failed");
+      error.code = "TEST_RUNTIME_QUERY_FAILED";
+      throw error;
+    }
+  };
+  const server = createCloudApiServer({ accessController, traceStore, runtimeStore, codeAgentChatResults: results });
+  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
+
+  try {
+    const { port } = server.address();
+    const turn = await getJson(port, `/v1/workbench/turns/${encodeURIComponent(traceId)}`);
+    assert.equal(turn.status, 200);
+    assert.equal(turn.body.turn.status, "running");
+    assert.equal(turn.body.projectionHealth, "unavailable");
+    assert.equal(turn.body.projection.blocker.code, "projection_store_unavailable");
+    assert.equal(turn.body.blocker.code, "projection_store_unavailable");
+
+    const trace = await getJson(port, `/v1/workbench/traces/${encodeURIComponent(traceId)}/events?limit=10`);
+    assert.equal(trace.status, 200);
+    assert.equal(trace.body.events.length, 1);
+    assert.equal(trace.body.traceStatus, "running");
+    assert.equal(trace.body.projectionHealth, "unavailable");
+    assert.equal(trace.body.projection.blocker.code, "projection_store_unavailable");
+  } finally {
+    await new Promise((resolve, reject) => server.close((error) => error ? reject(error) : resolve()));
+  }
+});
+
 async function getJson(port, path) {
   const response = await fetch(`http://127.0.0.1:${port}${path}`);
   return {
diff --git a/internal/cloud/server-workbench-http.ts b/internal/cloud/server-workbench-http.ts
index 2a1938c8..42342c6a 100644
--- a/internal/cloud/server-workbench-http.ts
+++ b/internal/cloud/server-workbench-http.ts
@@ -306,9 +306,11 @@ async function handleWorkbenchTurnSnapshot(response, url, options, actor, rawTur
     turn: turnSnapshot({ projection: turnProjection, result, session, trace }),
     projection,
     projectionStatus: projection.projectionStatus,
+    projectionHealth: projection.projectionHealth,
     lastProjectedSeq: projection.lastProjectedSeq,
     sourceRunId: projection.sourceRunId,
     sourceCommandId: projection.sourceCommandId,
+    staleMs: projection.staleMs,
     blocker: projection.blocker,
     valuesRedacted: true,
     secretMaterialStored: false
@@ -342,9 +344,11 @@ async function handleWorkbenchTraceEventPage(response, url, options, actor, rawT
     ...page,
     projection,
     projectionStatus: projection.projectionStatus,
+    projectionHealth: projection.projectionHealth,
     lastProjectedSeq: projection.lastProjectedSeq,
     sourceRunId: projection.sourceRunId,
     sourceCommandId: projection.sourceCommandId,
+    staleMs: projection.staleMs,
     blocker: projection.blocker,
     valuesRedacted: true,
     secretMaterialStored: false
@@ -385,13 +389,15 @@ async function sessionProjectionOptions(readModel, session, options) {
   const trace = await readModel.traceSnapshot(traceId);
   const result = readModel.resultForTrace(traceId);
   const projection = createWorkbenchTurnProjection({ traceId, result, session, trace });
-  return { ...options, trace, result, projection };
+  const projectionDiagnostic = readModel.projectionDiagnostics({ traceId, result, trace, projection });
+  return { ...options, trace, result, projection, projectionDiagnostic };
 }
 
 function sessionSummary(session, options) {
   if (!session?.id) return null;
   const snapshot = objectValue(session.session);
   const currentTurn = currentWorkbenchTurnProjection(session, options);
+  const projectionDiagnostic = options.projectionDiagnostic ?? null;
   const messages = sessionMessages(session, { ...options, currentTurn });
   const status = currentTurn ? currentTurn.status : sessionLifecycleProjectionStatus(session);
   return {
@@ -402,6 +408,11 @@ function sessionSummary(session, options) {
     running: RUNNING_STATUSES.has(status),
     terminal: TERMINAL_STATUSES.has(status) && !RUNNING_STATUSES.has(status),
     lastTraceId: currentTurn ? currentTurn.traceId : null,
+    projection: projectionDiagnostic,
+    projectionStatus: projectionDiagnostic?.projectionStatus ?? null,
+    projectionHealth: projectionDiagnostic?.projectionHealth ?? null,
+    staleMs: projectionDiagnostic?.staleMs ?? null,
+    blocker: projectionDiagnostic?.blocker ?? null,
     providerProfile: textValue(snapshot.providerProfile) || null,
     messageCount: messages.length,
     firstUserMessagePreview: firstUserPreview(messages),
@@ -413,6 +424,11 @@ function sessionSummary(session, options) {
       running: RUNNING_STATUSES.has(status),
       terminal: TERMINAL_STATUSES.has(status) && !RUNNING_STATUSES.has(status),
       eventCount: currentTurn.eventCount,
+      projection: projectionDiagnostic,
+      projectionStatus: projectionDiagnostic?.projectionStatus ?? null,
+      projectionHealth: projectionDiagnostic?.projectionHealth ?? null,
+      staleMs: projectionDiagnostic?.staleMs ?? null,
+      blocker: projectionDiagnostic?.blocker ?? null,
       updatedAt: currentTurn.updatedAt
     } : null,
     valuesRedacted: true
@@ -442,7 +458,8 @@ function sessionMessages(session, options = {}) {
   const messages = raw
     .map((message, index) => messageFact(message, index, session, snapshot))
     .filter(Boolean)
-    .map((message) => applyTerminalMessageProjection(message, terminalProjection));
+    .map((message) => applyTerminalMessageProjection(message, terminalProjection))
+    .map((message) => applyProjectionMessageDiagnostic(message, options.projectionDiagnostic, currentTurn));
   const hasAssistantLikeFinal = messages.some((message) => isAssistantLikeRole(message.role) && (!finalTraceId || message.traceId === finalTraceId));
   const finalText = terminalProjection?.text ?? projectionText(snapshot.finalResponse);
   if (!hasAssistantLikeFinal && finalText) {
@@ -453,6 +470,21 @@ function sessionMessages(session, options = {}) {
   return messages;
 }
 
+function applyProjectionMessageDiagnostic(message, diagnostic, currentTurn) {
+  if (!diagnostic || !isAssistantLikeRole(message.role)) return message;
+  if (currentTurn?.traceId && message.traceId && message.traceId !== currentTurn.traceId) return message;
+  const trace = message.runnerTrace && typeof message.runnerTrace === "object" ? message.runnerTrace : null;
+  return {
+    ...message,
+    projection: diagnostic,
+    projectionStatus: diagnostic.projectionStatus ?? null,
+    projectionHealth: diagnostic.projectionHealth ?? null,
+    staleMs: diagnostic.staleMs ?? null,
+    blocker: diagnostic.blocker ?? null,
+    runnerTrace: trace ? { ...trace, projection: diagnostic, projectionStatus: diagnostic.projectionStatus ?? null, projectionHealth: diagnostic.projectionHealth ?? null, staleMs: diagnostic.staleMs ?? null, blocker: diagnostic.blocker ?? null } : trace
+  };
+}
+
 function terminalMessageProjection(snapshot, options, currentTurn) {
   if (!currentTurn) return null;
   const traceId = currentTurn.traceId;
diff --git a/internal/cloud/workbench-facts-store.ts b/internal/cloud/workbench-facts-store.ts
index d4cd6a0c..27451569 100644
--- a/internal/cloud/workbench-facts-store.ts
+++ b/internal/cloud/workbench-facts-store.ts
@@ -76,6 +76,7 @@ export function createWorkbenchFactsStore(options = {}, actor = null) {
     const memory = traceSnapshotSync(traceId);
     if (hasTraceProjection(memory) && TERMINAL_STATUSES.has(normalizeStatus(memory.status))) return memory;
     const durable = await durableTraceSnapshot(runtimeStore, traceId);
+    if (isProjectionDiagnosticTrace(durable) && hasTraceProjection(memory)) return mergeTraceProjectionDiagnostic(memory, durable);
     if (durable && shouldPreferDurableTrace(memory, durable)) return durable;
     if (hasTraceProjection(memory)) return memory;
     return durable ?? memory;
@@ -103,8 +104,8 @@ async function durableTraceSnapshot(runtimeStore, traceId) {
   let result;
   try {
     result = await runtimeStore.queryAgentTraceEvents({ traceId });
-  } catch {
-    return null;
+  } catch (error) {
+    return projectionStoreUnavailableTrace(traceId, error);
   }
   const events = Array.isArray(result?.events) ? result.events : [];
   if (events.length === 0) return null;
@@ -131,6 +132,51 @@ async function durableTraceSnapshot(runtimeStore, traceId) {
   };
 }
 
+function projectionStoreUnavailableTrace(traceId, error) {
+  const message = "运行记录投影存储暂不可读，Trace 更新暂不可见。";
+  const projection = {
+    projectionStatus: "blocked",
+    projectionHealth: "unavailable",
+    blocker: {
+      code: "projection_store_unavailable",
+      layer: "runtime-store",
+      category: "projection-store-unavailable",
+      message,
+      causeCode: error?.code ?? null,
+      retryable: true,
+      valuesPrinted: false
+    },
+    valuesRedacted: true
+  };
+  return {
+    traceId,
+    status: "missing",
+    eventCount: 0,
+    events: [],
+    projection,
+    projectionStatus: projection.projectionStatus,
+    projectionHealth: projection.projectionHealth,
+    blocker: projection.blocker,
+    updatedAt: new Date().toISOString(),
+    valuesPrinted: false
+  };
+}
+
+function isProjectionDiagnosticTrace(snapshot) {
+  return Boolean(snapshot?.projection?.blocker || snapshot?.projectionHealth || snapshot?.blocker);
+}
+
+function mergeTraceProjectionDiagnostic(memory, diagnostic) {
+  return {
+    ...memory,
+    projection: diagnostic.projection ?? memory?.projection ?? null,
+    projectionStatus: diagnostic.projectionStatus ?? diagnostic.projection?.projectionStatus ?? memory?.projectionStatus ?? null,
+    projectionHealth: diagnostic.projectionHealth ?? diagnostic.projection?.projectionHealth ?? memory?.projectionHealth ?? null,
+    blocker: diagnostic.blocker ?? diagnostic.projection?.blocker ?? memory?.blocker ?? null,
+    valuesPrinted: false
+  };
+}
+
 function hasTraceProjection(snapshot) {
   return Boolean(snapshot?.status !== "missing" && (Number(snapshot?.eventCount ?? 0) > 0 || snapshot?.lastEvent));
 }
diff --git a/internal/cloud/workbench-read-model.ts b/internal/cloud/workbench-read-model.ts
index c2b3f2f2..7219bdc3 100644
--- a/internal/cloud/workbench-read-model.ts
+++ b/internal/cloud/workbench-read-model.ts
@@ -18,6 +18,6 @@ export function createWorkbenchReadModel(options = {}, actor = null) {
     traceSnapshotSync: (traceId) => facts.traceSnapshotSync(traceId),
     subscribeTrace: (traceId, listener) => facts.subscribeTrace(traceId, listener),
     canReadOwner: (ownerUserId) => facts.canReadOwner(ownerUserId),
-    projectionDiagnostics: ({ traceId, result = null, trace = null, projection = null } = {}) => workbenchProjectionDiagnostics({ traceId, result, trace, projection })
+    projectionDiagnostics: ({ traceId, result = null, trace = null, projection = null, refreshError = null } = {}) => workbenchProjectionDiagnostics({ traceId, result, trace, projection, refreshError })
   };
 }
diff --git a/internal/cloud/workbench-turn-projection.ts b/internal/cloud/workbench-turn-projection.ts
index c60a92ac..baa65cb4 100644
--- a/internal/cloud/workbench-turn-projection.ts
+++ b/internal/cloud/workbench-turn-projection.ts
@@ -36,17 +36,25 @@ export function createWorkbenchTurnProjection({ turnId = null, traceId = null, r
   };
 }
 
-export function projectionDiagnostics({ traceId = null, projection = null, result = null, trace = null } = {}) {
+export function projectionDiagnostics({ traceId = null, projection = null, result = null, trace = null, refreshError = null } = {}) {
   const turn = projection ?? createWorkbenchTurnProjection({ traceId, result, trace });
-  const blocker = result?.blocker ?? result?.error ?? null;
+  const source = projectionDiagnosticSource(trace);
+  const blocker = refreshError ?? source?.blocker ?? trace?.blocker ?? result?.blocker ?? result?.error ?? null;
   const hasProjectionInput = hasTraceProjection(trace) || Boolean(result || result?.agentRun);
-  const status = blocker ? "blocked" : turn.terminal ? "caught-up" : hasProjectionInput ? "projecting" : "unknown";
+  const sourceStatus = normalizeProjectionStatus(source?.projectionStatus ?? trace?.projectionStatus);
+  const status = sourceStatus ?? (blocker ? "blocked" : turn.terminal ? "caught-up" : hasProjectionInput ? "projecting" : "unknown");
+  const diagnostic = blocker ? diagnosticBlocker(blocker) : null;
+  const projectionHealth = normalizeProjectionHealth(source?.projectionHealth ?? trace?.projectionHealth)
+    ?? projectionHealthFor({ status, turn, hasProjectionInput, blocker: diagnostic });
+  const staleMs = projectionStaleMs(source?.staleMs ?? trace?.staleMs, turn.updatedAt ?? trace?.updatedAt ?? result?.updatedAt);
   return {
     projectionStatus: status,
+    projectionHealth,
     lastProjectedSeq: turn.lastProjectedSeq ?? null,
     sourceRunId: turn.sourceRunId ?? null,
     sourceCommandId: turn.sourceCommandId ?? null,
-    blocker: blocker ? diagnosticBlocker(blocker) : null,
+    staleMs,
+    blocker: diagnostic,
     updatedAt: turn.updatedAt ?? null,
     valuesRedacted: true
   };
@@ -166,6 +174,38 @@ function traceLastEvent(trace) {
   return trace?.lastEvent ?? events.at(-1) ?? null;
 }
 
+function projectionDiagnosticSource(trace) {
+  const direct = objectValue(trace?.projection);
+  if (direct) return direct;
+  if (trace?.projectionHealth || trace?.projectionStatus || trace?.blocker) return trace;
+  return null;
+}
+
+function normalizeProjectionStatus(value) {
+  const text = String(value ?? "").trim().toLowerCase().replace(/_/gu, "-");
+  return ["caught-up", "projecting", "blocked", "stalled", "unknown"].includes(text) ? text : null;
+}
+
+function normalizeProjectionHealth(value) {
+  const text = String(value ?? "").trim().toLowerCase().replace(/_/gu, "-");
+  return ["caught-up", "degraded", "stalled", "unavailable", "unknown"].includes(text) ? text : null;
+}
+
+function projectionHealthFor({ status, turn, hasProjectionInput, blocker }) {
+  if (blocker?.code === "projection_store_unavailable") return "unavailable";
+  if (blocker) return status === "stalled" ? "stalled" : "degraded";
+  if (turn.terminal || status === "caught-up" || hasProjectionInput) return "caught-up";
+  return "unknown";
+}
+
+function projectionStaleMs(value, updatedAt) {
+  const direct = Number(value);
+  if (Number.isFinite(direct) && direct >= 0) return Math.trunc(direct);
+  const updatedAtMs = Date.parse(String(updatedAt ?? ""));
+  if (!Number.isFinite(updatedAtMs)) return null;
+  return Math.max(0, Date.now() - updatedAtMs);
+}
+
 function eventSeq(event, index) {
   const seq = Number(event?.seq);
   return Number.isFinite(seq) && seq > 0 ? Math.trunc(seq) : index + 1;
@@ -196,8 +236,15 @@ function diagnosticBlocker(value = {}) {
   if (!value || typeof value !== "object") return { code: "projection_blocked", summary: String(value), valuesRedacted: true };
   return {
     code: String(value.code ?? value.errorCode ?? "projection_blocked"),
+    layer: textValue(value.layer ?? value.source) || null,
+    category: textValue(value.category ?? value.type) || null,
     summary: String(value.summary ?? value.userMessage ?? value.message ?? value.code ?? "Projection is blocked."),
+    message: textValue(value.message ?? value.summary ?? value.userMessage) || null,
+    userMessage: textValue(value.userMessage ?? value.zh) || null,
     retryable: typeof value.retryable === "boolean" ? value.retryable : null,
+    runId: textValue(value.runId) || null,
+    commandId: textValue(value.commandId) || null,
+    timeoutMs: Number.isFinite(Number(value.timeoutMs)) ? Math.trunc(Number(value.timeoutMs)) : null,
     valuesRedacted: true
   };
 }
diff --git a/web/hwlab-cloud-web/scripts/workbench-e2e-server.ts b/web/hwlab-cloud-web/scripts/workbench-e2e-server.ts
index a50fb64d..b7879b9b 100644
--- a/web/hwlab-cloud-web/scripts/workbench-e2e-server.ts
+++ b/web/hwlab-cloud-web/scripts/workbench-e2e-server.ts
@@ -111,13 +111,14 @@ async function handleRequest(request: IncomingMessage, response: ServerResponse)
     const traceId = decodeURIComponent(turnMatch[1] ?? "");
     if (state.scenarioId === "completed-replay-detail-404" && traceId === "trc_completed") return json(response, 404, { ok: false, status: 404, error: { code: "turn_replay_unavailable" } });
     if (traceId === state.staleTraceId) return json(response, 502, { ok: false, status: 502, error: { code: "upstream_unavailable", message: "stale trace is unavailable" } });
-    return json(response, 200, { ok: true, status: "ok", contractVersion: "workbench-read-model-v1", turn: turnPayload(traceId) });
+    return json(response, 200, workbenchTurnPayload(traceId));
   }
 
   const traceMatch = path.match(/^\/v1\/workbench\/traces\/([^/]+)\/events$/u);
   if (traceMatch && method === "GET") {
     const traceId = decodeURIComponent(traceMatch[1] ?? "");
     if (state.scenarioId === "completed-replay-detail-404" && traceId === "trc_completed") return json(response, 404, { ok: false, status: 404, error: { code: "trace_replay_unavailable" } });
+    if (state.scenarioId === "trace-hydration-timeout-diagnostic" && traceId === "trc_trace_hydration_timeout") return json(response, 504, { ok: false, status: 504, error: { code: "trace_hydration_timeout", message: "Trace 更新超时，运行记录暂不可见。" } });
     if (traceId === state.staleTraceId) return json(response, 502, { ok: false, status: 502, error: { code: "upstream_unavailable", message: "stale trace is unavailable" } });
     return json(response, 200, workbenchTracePayload(traceId, url));
   }
@@ -283,6 +284,18 @@ function createScenarioState(scenarioId: string): ScenarioState {
   if (id === "progress-only-final-response") markRunningProgressOnly(sessions, traces);
   if (id === "terminal-completed-no-final-response") markRunningNoFinalResponse(sessions, traces);
   if (id === "tool-completed-projection-running") markToolCompletedProjectionRunning(sessions, traces);
+  if (id === "projection-degraded-diagnostics") {
+    sessions.unshift(projectionDegradedSession());
+    traces.trc_projection_degraded = projectionDegradedTrace();
+  }
+  if (id === "projection-sse-error") {
+    sessions.unshift(projectionSseErrorSession());
+    traces.trc_projection_sse_error = projectionSseErrorTrace();
+  }
+  if (id === "trace-hydration-timeout-diagnostic") {
+    sessions.unshift(traceHydrationTimeoutSession());
+    traces.trc_trace_hydration_timeout = traceHydrationTimeoutTrace();
+  }
   if (id === "scroll-follow-long-trace") {
     const session = scrollFollowSession();
     sessions.unshift(session);
@@ -307,6 +320,12 @@ function createScenarioState(scenarioId: string): ScenarioState {
         ? "ses_terminal_empty"
         : id === "progress-only-final-response" || id === "terminal-completed-no-final-response" || id === "tool-completed-projection-running"
           ? "ses_running"
+        : id === "projection-degraded-diagnostics"
+          ? "ses_projection_degraded"
+        : id === "projection-sse-error"
+          ? "ses_projection_sse_error"
+        : id === "trace-hydration-timeout-diagnostic"
+          ? "ses_trace_hydration_timeout"
         : id === "create-while-route-loading"
           ? "ses_running"
           : base.selectedSessionId;
@@ -413,6 +432,95 @@ function toolCompletedProjectionRunningTrace(): JsonRecord {
   };
 }
 
+function projectionDiagnostic(input: { code: string; message: string; health?: string; category?: string; layer?: string; traceId: string; runId?: string; commandId?: string; staleMs?: number }): JsonRecord {
+  return {
+    projectionStatus: "projecting",
+    projectionHealth: input.health ?? "degraded",
+    lastProjectedSeq: 137,
+    sourceRunId: input.runId ?? "run_projection_diag",
+    sourceCommandId: input.commandId ?? "cmd_projection_diag",
+    staleMs: input.staleMs ?? 12_345,
+    blocker: {
+      code: input.code,
+      layer: input.layer ?? "agentrun",
+      category: input.category ?? "upstream-timeout",
+      message: input.message,
+      retryable: true,
+      timeoutMs: 2500,
+      runId: input.runId ?? "run_projection_diag",
+      commandId: input.commandId ?? "cmd_projection_diag",
+      valuesPrinted: false
+    },
+    valuesRedacted: true
+  };
+}
+
+function projectionDegradedTrace(): JsonRecord {
+  const projection = projectionDiagnostic({ traceId: "trc_projection_degraded", code: "agentrun_result_timeout", message: "状态更新超时，最近投影 seq=137，AgentRun 结果暂不可见。" });
+  return { traceId: "trc_projection_degraded", status: "running", sessionId: "ses_projection_degraded", threadId: "thr_projection_degraded", turnId: "turn_projection_degraded", events: [], eventCount: 0, fullTraceLoaded: true, hasMore: false, projection, ...projection };
+}
+
+function projectionDegradedSession(): SessionRecord {
+  const now = new Date().toISOString();
+  const projection = projectionDiagnostic({ traceId: "trc_projection_degraded", code: "agentrun_result_timeout", message: "状态更新超时，最近投影 seq=137，AgentRun 结果暂不可见。" });
+  return {
+    sessionId: "ses_projection_degraded",
+    threadId: "thr_projection_degraded",
+    status: "running",
+    lastTraceId: "trc_projection_degraded",
+    updatedAt: now,
+    messageCount: 2,
+    firstUserMessagePreview: "projection degraded visibility",
+    turnSummary: { traceId: "trc_projection_degraded", status: "running", running: true, terminal: false, ...projection },
+    messages: [
+      { id: "msg_projection_degraded_user", messageId: "msg_projection_degraded_user", role: "user", title: "用户", text: "projection degraded visibility", status: "sent", createdAt: now, sessionId: "ses_projection_degraded", threadId: "thr_projection_degraded", turnId: "turn_projection_degraded" },
+      { id: "msg_projection_degraded_agent", messageId: "msg_projection_degraded_agent", role: "agent", title: "Code Agent", text: "", status: "running", createdAt: now, sessionId: "ses_projection_degraded", threadId: "thr_projection_degraded", traceId: "trc_projection_degraded", turnId: "turn_projection_degraded", projection, runnerTrace: projectionDegradedTrace() }
+    ]
+  };
+}
+
+function projectionSseErrorTrace(): JsonRecord {
+  return { traceId: "trc_projection_sse_error", status: "running", sessionId: "ses_projection_sse_error", threadId: "thr_projection_sse_error", turnId: "turn_projection_sse_error", events: [], eventCount: 0, fullTraceLoaded: false, hasMore: false };
+}
+
+function projectionSseErrorSession(): SessionRecord {
+  const now = new Date().toISOString();
+  return {
+    sessionId: "ses_projection_sse_error",
+    threadId: "thr_projection_sse_error",
+    status: "running",
+    lastTraceId: "trc_projection_sse_error",
+    updatedAt: now,
+    messageCount: 2,
+    firstUserMessagePreview: "projection SSE error visibility",
+    messages: [
+      { id: "msg_projection_sse_error_user", messageId: "msg_projection_sse_error_user", role: "user", title: "用户", text: "projection SSE error visibility", status: "sent", createdAt: now, sessionId: "ses_projection_sse_error", threadId: "thr_projection_sse_error", turnId: "turn_projection_sse_error" },
+      { id: "msg_projection_sse_error_agent", messageId: "msg_projection_sse_error_agent", role: "agent", title: "Code Agent", text: "", status: "running", createdAt: now, sessionId: "ses_projection_sse_error", threadId: "thr_projection_sse_error", traceId: "trc_projection_sse_error", turnId: "turn_projection_sse_error", runnerTrace: projectionSseErrorTrace() }
+    ]
+  };
+}
+
+function traceHydrationTimeoutTrace(): JsonRecord {
+  return { traceId: "trc_trace_hydration_timeout", status: "running", sessionId: "ses_trace_hydration_timeout", threadId: "thr_trace_hydration_timeout", turnId: "turn_trace_hydration_timeout", events: [], eventCount: 0, fullTraceLoaded: false, hasMore: true };
+}
+
+function traceHydrationTimeoutSession(): SessionRecord {
+  const now = new Date().toISOString();
+  return {
+    sessionId: "ses_trace_hydration_timeout",
+    threadId: "thr_trace_hydration_timeout",
+    status: "running",
+    lastTraceId: "trc_trace_hydration_timeout",
+    updatedAt: now,
+    messageCount: 2,
+    firstUserMessagePreview: "trace hydration timeout visibility",
+    messages: [
+      { id: "msg_trace_hydration_timeout_user", messageId: "msg_trace_hydration_timeout_user", role: "user", title: "用户", text: "trace hydration timeout visibility", status: "sent", createdAt: now, sessionId: "ses_trace_hydration_timeout", threadId: "thr_trace_hydration_timeout", turnId: "turn_trace_hydration_timeout" },
+      { id: "msg_trace_hydration_timeout_agent", messageId: "msg_trace_hydration_timeout_agent", role: "agent", title: "Code Agent", text: "", status: "running", createdAt: now, sessionId: "ses_trace_hydration_timeout", threadId: "thr_trace_hydration_timeout", traceId: "trc_trace_hydration_timeout", turnId: "turn_trace_hydration_timeout", runnerTrace: traceHydrationTimeoutTrace() }
+    ]
+  };
+}
+
 function noFinalRunningTrace(): JsonRecord {
   const createdAt = new Date().toISOString();
   return {
@@ -921,6 +1029,11 @@ function turnPayload(traceId: string): JsonRecord {
   return { ...trace, traceId, status, running: ["running", "pending", "accepted"].includes(status), terminal: ["completed", "failed", "blocked", "timeout", "canceled"].includes(status) };
 }
 
+function workbenchTurnPayload(traceId: string): JsonRecord {
+  const turn = turnPayload(traceId);
+  return { ok: true, status: "ok", contractVersion: "workbench-read-model-v1", turn, ...projectionEnvelope(turn) };
+}
+
 function tracePayload(traceId: string, url: URL): JsonRecord {
   const turn = turnPayload(traceId);
   const events = Array.isArray(turn.events) ? turn.events as JsonRecord[] : [];
@@ -939,7 +1052,22 @@ function workbenchTracePayload(traceId: string, url: URL): JsonRecord {
   if (state.scenarioId === "tool-completed-projection-running" && traceId === "trc_running") {
     return { ok: true, status: "ok", contractVersion: "workbench-read-model-v1", traceId, sessionId: payload.sessionId ?? null, threadId: payload.threadId ?? null, traceStatus: "completed", events: payload.events, eventCount: payload.eventCount, hasMore: payload.hasMore, nextSeq: payload.nextSinceSeq, range: payload.range, fullTraceLoaded: payload.fullTraceLoaded, projectionStatus: "projecting", terminalEvidence: null, finalResponse: null, traceSummary: payload.traceSummary, retention: payload.retention };
   }
-  return { ok: true, status: "ok", contractVersion: "workbench-read-model-v1", traceId, sessionId: payload.sessionId ?? null, threadId: payload.threadId ?? null, traceStatus: payload.status, events: payload.events, eventCount: payload.eventCount, hasMore: payload.hasMore, nextSeq: payload.nextSinceSeq, range: payload.range, fullTraceLoaded: payload.fullTraceLoaded, terminalEvidence: payload.terminalEvidence, finalResponse: payload.finalResponse, traceSummary: payload.traceSummary, retention: payload.retention };
+  return { ok: true, status: "ok", contractVersion: "workbench-read-model-v1", traceId, sessionId: payload.sessionId ?? null, threadId: payload.threadId ?? null, traceStatus: payload.status, events: payload.events, eventCount: payload.eventCount, hasMore: payload.hasMore, nextSeq: payload.nextSinceSeq, range: payload.range, fullTraceLoaded: payload.fullTraceLoaded, terminalEvidence: payload.terminalEvidence, finalResponse: payload.finalResponse, traceSummary: payload.traceSummary, retention: payload.retention, ...projectionEnvelope(payload) };
+}
+
+function projectionEnvelope(payload: JsonRecord): JsonRecord {
+  const projection = payload.projection && typeof payload.projection === "object" ? payload.projection as JsonRecord : null;
+  if (!projection) return {};
+  return {
+    projection,
+    projectionStatus: projection.projectionStatus,
+    projectionHealth: projection.projectionHealth,
+    lastProjectedSeq: projection.lastProjectedSeq,
+    sourceRunId: projection.sourceRunId,
+    sourceCommandId: projection.sourceCommandId,
+    staleMs: projection.staleMs,
+    blocker: projection.blocker
+  };
 }
 
 function sse(request: IncomingMessage, response: ServerResponse, url: URL): void {
@@ -947,6 +1075,14 @@ function sse(request: IncomingMessage, response: ServerResponse, url: URL): void
   sseClients.add(response);
   request.on("close", () => sseClients.delete(response));
   writeSse(response, "workbench.connected", { type: "connected", sessionId: url.searchParams.get("sessionId") });
+  if (state.scenarioId === "projection-sse-error") {
+    const scenarioId = state.scenarioId;
+    setTimeout(() => {
+      if (state.scenarioId !== scenarioId) return;
+      const projection = projectionDiagnostic({ traceId: "trc_projection_sse_error", code: "workbench_sse_projection_error", message: "SSE 投影事件异常，实时状态暂不可见。", category: "realtime-error", layer: "workbench-sse", runId: "run_projection_sse_error", commandId: "cmd_projection_sse_error" });
+      writeSse(response, "workbench.error", { type: "error", sessionId: "ses_projection_sse_error", threadId: "thr_projection_sse_error", traceId: "trc_projection_sse_error", projection, ...projectionEnvelope({ projection }), error: projection.blocker });
+    }, 350);
+  }
   if (state.scenarioId === "cross-session-late-events") {
     const scenarioId = state.scenarioId;
     setTimeout(() => {
diff --git a/web/hwlab-cloud-web/src/api/workbench-events.ts b/web/hwlab-cloud-web/src/api/workbench-events.ts
index 7f8a7813..08002410 100644
--- a/web/hwlab-cloud-web/src/api/workbench-events.ts
+++ b/web/hwlab-cloud-web/src/api/workbench-events.ts
@@ -1,7 +1,7 @@
 // SPEC: PJ2026-010403 API契约 draft-2026-06-18-r1; PJ2026-010401 Web工作台 draft-2026-06-18-r1; PJ2026-01060505 Workbench Performance draft-2026-06-17-p0.
 // Responsibility: Workbench SSE client. Realtime events accelerate UI projection; REST snapshots remain gap-fill authority.
 
-import type { TraceEvent } from "@/types";
+import type { ProjectionDiagnostic, TraceEvent } from "@/types";
 
 export interface WorkbenchRealtimeTraceSnapshot {
   traceId?: string | null;
@@ -10,6 +10,11 @@ export interface WorkbenchRealtimeTraceSnapshot {
   eventCount?: number | null;
   lastEvent?: TraceEvent | null;
   updatedAt?: string | null;
+  projection?: ProjectionDiagnostic | null;
+  projectionStatus?: string | null;
+  projectionHealth?: string | null;
+  staleMs?: number | null;
+  blocker?: ProjectionDiagnostic["blocker"] | null;
   [key: string]: unknown;
 }
 
@@ -25,7 +30,7 @@ export interface WorkbenchRealtimeEvent {
   snapshot?: WorkbenchRealtimeTraceSnapshot | null;
   turn?: Record<string, unknown> | null;
   reason?: string | null;
-  error?: { code?: string; message?: string } | null;
+  error?: { code?: string; message?: string; [key: string]: unknown } | null;
   traceSeq?: number | null;
   cursor?: { traceSeq?: number | null; [key: string]: unknown };
   [key: string]: unknown;
diff --git a/web/hwlab-cloud-web/src/api/workbench.ts b/web/hwlab-cloud-web/src/api/workbench.ts
index 120b3f7f..4d0f2aae 100644
--- a/web/hwlab-cloud-web/src/api/workbench.ts
+++ b/web/hwlab-cloud-web/src/api/workbench.ts
@@ -2,7 +2,7 @@
 // Responsibility: Workbench read-model HTTP client for session, message, turn and trace projection APIs.
 
 import { fetchJson, type ApiRequestOptions } from "./client";
-import type { AgentChatResultResponse, ApiResult, ChatMessage, WorkbenchSessionRecord } from "@/types";
+import type { AgentChatResultResponse, ApiResult, ChatMessage, ProjectionDiagnostic, WorkbenchSessionRecord } from "@/types";
 
 export interface WorkbenchSessionListResponse {
   sessions?: WorkbenchSessionRecord[];
@@ -92,13 +92,19 @@ function normalizeWorkbenchTurnResult(result: ApiResult<Record<string, unknown>>
   const turn = recordValue(result.data.turn) ?? result.data;
   const trace = recordValue(turn.trace);
   const status = normalizeStatus(textValue(turn.status)) ?? "unknown";
+  const projection = normalizeProjectionDiagnostic(result.data.projection, turn.projection, result.data);
   return {
     ...result,
     data: {
       ...turn,
-      projection: recordValue(result.data.projection) ?? undefined,
-      projectionStatus: textValue(result.data.projectionStatus) ?? undefined,
+      projection,
+      projectionStatus: projection?.projectionStatus ?? textValue(result.data.projectionStatus) ?? undefined,
+      projectionHealth: projection?.projectionHealth ?? textValue(result.data.projectionHealth) ?? undefined,
       lastProjectedSeq: Number.isFinite(Number(result.data.lastProjectedSeq)) ? Number(result.data.lastProjectedSeq) : undefined,
+      sourceRunId: projection?.sourceRunId ?? textValue(result.data.sourceRunId) ?? undefined,
+      sourceCommandId: projection?.sourceCommandId ?? textValue(result.data.sourceCommandId) ?? undefined,
+      staleMs: projection?.staleMs ?? numberValue(result.data.staleMs) ?? undefined,
+      blocker: projection?.blocker ?? recordValue(result.data.blocker) ?? undefined,
       traceId: textValue(turn.traceId) ?? traceId,
       status,
       running: typeof turn.running === "boolean" ? turn.running : undefined,
@@ -120,6 +126,7 @@ function normalizeWorkbenchTraceResult(result: ApiResult<Record<string, unknown>
   const normalizedNextSeq = Number.isFinite(nextSeq) ? Math.trunc(nextSeq) : null;
   const hasMore = result.data.hasMore === true;
   const fullTraceLoaded = typeof result.data.fullTraceLoaded === "boolean" ? result.data.fullTraceLoaded : undefined;
+  const projection = normalizeProjectionDiagnostic(result.data.projection, result.data);
   return {
     ...result,
     data: {
@@ -132,6 +139,11 @@ function normalizeWorkbenchTraceResult(result: ApiResult<Record<string, unknown>
       eventCount,
       hasMore,
       fullTraceLoaded,
+      projection,
+      projectionStatus: projection?.projectionStatus ?? textValue(result.data.projectionStatus) ?? undefined,
+      projectionHealth: projection?.projectionHealth ?? textValue(result.data.projectionHealth) ?? undefined,
+      staleMs: projection?.staleMs ?? numberValue(result.data.staleMs) ?? undefined,
+      blocker: projection?.blocker ?? recordValue(result.data.blocker) ?? undefined,
       nextSinceSeq: normalizedNextSeq,
       range: recordValue(result.data.range) ?? undefined,
       runnerTrace: {
@@ -143,6 +155,11 @@ function normalizeWorkbenchTraceResult(result: ApiResult<Record<string, unknown>
         fullTraceLoaded,
         nextSinceSeq: normalizedNextSeq,
         range: recordValue(result.data.range) ?? undefined,
+        projection,
+        projectionStatus: projection?.projectionStatus ?? textValue(result.data.projectionStatus) ?? undefined,
+        projectionHealth: projection?.projectionHealth ?? textValue(result.data.projectionHealth) ?? undefined,
+        staleMs: projection?.staleMs ?? numberValue(result.data.staleMs) ?? undefined,
+        blocker: projection?.blocker ?? recordValue(result.data.blocker) ?? undefined,
         eventSource: "trace-api"
       }
     } as AgentChatResultResponse
@@ -160,6 +177,39 @@ function recordValue(value: unknown): Record<string, unknown> | null {
   return value && typeof value === "object" ? value as Record<string, unknown> : null;
 }
 
+function normalizeProjectionDiagnostic(...values: unknown[]): ProjectionDiagnostic | undefined {
+  for (const value of values) {
+    const record = recordValue(value);
+    if (!record) continue;
+    const source = recordValue(record.projection) ?? record;
+    const blocker = recordValue(source.blocker ?? record.blocker);
+    const projectionStatus = textValue(source.projectionStatus ?? record.projectionStatus);
+    const projectionHealth = textValue(source.projectionHealth ?? record.projectionHealth);
+    const lastProjectedSeq = numberValue(source.lastProjectedSeq ?? record.lastProjectedSeq);
+    const staleMs = numberValue(source.staleMs ?? record.staleMs);
+    const sourceRunId = textValue(source.sourceRunId ?? record.sourceRunId);
+    const sourceCommandId = textValue(source.sourceCommandId ?? record.sourceCommandId);
+    if (!projectionStatus && !projectionHealth && !blocker && lastProjectedSeq == null && staleMs == null && !sourceRunId && !sourceCommandId) continue;
+    return {
+      ...source,
+      projectionStatus: projectionStatus ?? undefined,
+      projectionHealth: projectionHealth ?? undefined,
+      lastProjectedSeq,
+      sourceRunId: sourceRunId ?? undefined,
+      sourceCommandId: sourceCommandId ?? undefined,
+      staleMs,
+      blocker: blocker ?? null,
+      valuesRedacted: source.valuesRedacted !== false
+    } as ProjectionDiagnostic;
+  }
+  return undefined;
+}
+
+function numberValue(value: unknown): number | null {
+  const number = Number(value);
+  return Number.isFinite(number) ? number : null;
+}
+
 function textValue(...values: unknown[]): string | null {
   for (const value of values) {
     if (typeof value !== "string") continue;
diff --git a/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue b/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue
index 95eec8da..a4fc2faa 100644
--- a/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue
+++ b/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue
@@ -15,7 +15,14 @@ const { following, keepBottomAfterUpdate, onScroll, scrollToBottom } = useBottom
 const events = computed(() => Array.isArray(props.trace?.events) ? props.trace.events : []);
 const eventCount = computed(() => props.trace?.eventCount ?? events.value.length);
 const readableRows = computed(() => traceDisplayRows(traceRecord(props.trace), events.value as Record<string, unknown>[]));
+const projectionDiagnosticLabel = computed(() => {
+  const projection = props.trace?.projection ?? null;
+  const health = projection?.projectionHealth ?? props.trace?.projectionHealth;
+  if (!projection || health === "caught-up") return null;
+  return firstNonEmptyString(projection.blocker?.userMessage, projection.blocker?.message, projection.blocker?.summary, projection.blocker?.code ? `状态更新异常：${projection.blocker.code}` : null);
+});
 const emptyTraceLabel = computed(() => {
+  if (projectionDiagnosticLabel.value) return projectionDiagnosticLabel.value;
   if (isTerminalTraceStatus(props.trace?.status)) return terminalTraceEmptyLabel(props.trace?.status);
   if (events.value.length > 0 || (props.trace?.fullTraceLoaded === true && eventCount.value > 0)) return "暂无可读 Trace";
   return props.trace?.fullTraceLoaded === true ? "思考中..." : "加载中...";
@@ -106,10 +113,19 @@ function terminalTraceEmptyLabel(status: unknown): string {
   }
 }
 
+function firstNonEmptyString(...values: unknown[]): string | null {
+  for (const value of values) {
+    if (typeof value !== "string") continue;
+    const text = value.trim();
+    if (text) return text;
+  }
+  return null;
+}
+
 </script>
 
 <template>
-  <section v-if="trace" class="trace-timeline" :data-status="trace.status" :data-following="following ? 'true' : 'false'">
+  <section v-if="trace" class="trace-timeline" :data-status="trace.status" :data-projection-health="trace.projection?.projectionHealth || trace.projectionHealth || undefined" :data-following="following ? 'true' : 'false'">
     <details class="trace-disclosure" :open="expanded" @toggle="onDisclosureToggle">
       <summary class="trace-disclosure-summary" aria-label="折叠运行记录">
         <span class="trace-disclosure-caret" aria-hidden="true" />
diff --git a/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue b/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
index 01c01371..5a4e0882 100644
--- a/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
+++ b/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
@@ -84,10 +84,27 @@ function showMessageText(message: ChatMessage): boolean {
 }
 
 function messageDiagnosticText(message: ChatMessage): string | null {
+  if (message.role === "agent") return projectionDiagnosticText(message);
   if (message.role !== "user" || String(message.text ?? "").trim()) return null;
   return "消息内容缺失：Workbench read model 未返回 user text。";
 }
 
+function projectionDiagnosticText(message: ChatMessage): string | null {
+  const projection = message.projection ?? message.runnerTrace?.projection ?? null;
+  const health = projection?.projectionHealth ?? message.projectionHealth ?? message.runnerTrace?.projectionHealth;
+  if (!projection || health === "caught-up") return null;
+  return firstNonEmptyString(projection.blocker?.userMessage, projection.blocker?.message, projection.blocker?.summary, projection.blocker?.code ? `状态更新异常：${projection.blocker.code}` : null);
+}
+
+function firstNonEmptyString(...values: unknown[]): string | null {
+  for (const value of values) {
+    if (typeof value !== "string") continue;
+    const text = value.trim();
+    if (text) return text;
+  }
+  return null;
+}
+
 function acknowledgeVisibleMessages(): void {
   acknowledgeWorkbenchVisibleAfterPaint({ messages: workbench.activeMessages, activeSessionId: workbench.activeSessionId, detailLoading: workbench.sessionDetailLoading });
 }
diff --git a/web/hwlab-cloud-web/src/components/workbench/SessionRail.vue b/web/hwlab-cloud-web/src/components/workbench/SessionRail.vue
index 4e673694..000b7e67 100644
--- a/web/hwlab-cloud-web/src/components/workbench/SessionRail.vue
+++ b/web/hwlab-cloud-web/src/components/workbench/SessionRail.vue
@@ -111,8 +111,9 @@ function formatSessionUpdatedTime(value: string | null | undefined): string {
     <div v-if="!collapsed" class="session-list" id="session-tabs" :data-loading="showSessionListLoading">
       <LoadingState v-if="showSessionListLoading" class="session-list-loading" label="加载中" />
       <template v-else>
-        <button v-for="tab in workbench.sessionTabs" :key="tab.sessionId || tab.key" class="session-tab" :data-active="tab.active" :data-running="tab.running" :data-status="tab.status || undefined" :data-session-id="tab.sessionId || undefined" type="button" :title="tab.label || tab.sessionId || tab.key" @click="workbench.selectSession(tab)">
+        <button v-for="tab in workbench.sessionTabs" :key="tab.sessionId || tab.key" class="session-tab" :data-active="tab.active" :data-running="tab.running" :data-status="tab.status || undefined" :data-projection-health="tab.projectionHealth || undefined" :data-session-id="tab.sessionId || undefined" type="button" :title="tab.projectionDiagnosticText || tab.label || tab.sessionId || tab.key" @click="workbench.selectSession(tab)">
           <span class="session-tab-title">{{ tab.label || tab.sessionId }}</span>
+          <span v-if="tab.projectionDiagnosticText" class="session-tab-diagnostic">状态更新异常</span>
           <time class="session-tab-time" :datetime="tab.updatedAt || tab.startedAt || undefined">{{ formatSessionUpdatedTime(tab.updatedAt || tab.startedAt) }}</time>
         </button>
         <p v-if="workbench.sessionTabs.length === 0" class="muted-box">没有 session。发送前必须显式新建或选择 session。</p>
diff --git a/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts b/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts
index e6928f35..d77b0af2 100644
--- a/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts
+++ b/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts
@@ -2,7 +2,7 @@
 // Responsibility: Trace snapshot helpers and legacy subscription adapter backed by Workbench read-model APIs.
 
 import { workbenchAPI, type ActivityRefSource } from "@/api";
-import type { AgentChatResponse, AgentChatResultResponse, AgentRunProvenance, ChatMessage, TraceEvent } from "@/types";
+import type { AgentChatResponse, AgentChatResultResponse, AgentRunProvenance, ChatMessage, ProjectionDiagnostic, TraceEvent } from "@/types";
 import { firstNonEmptyString } from "@/utils";
 
 export interface TraceSnapshot {
@@ -27,6 +27,11 @@ export interface TraceSnapshot {
   error?: AgentChatResultResponse["error"];
   lastEventLabel?: string;
   waitingFor?: string;
+  projection?: ProjectionDiagnostic | null;
+  projectionStatus?: string | null;
+  projectionHealth?: string | null;
+  staleMs?: number | null;
+  blocker?: ProjectionDiagnostic["blocker"] | null;
   eventSource?: string;
   updatedAt?: string;
 }
@@ -83,6 +88,11 @@ export function snapshotToRunnerTrace(snapshot: TraceSnapshot): NonNullable<Chat
     sessionMode: snapshot.agentRun?.backendProfile,
     lastEventLabel: snapshot.lastEventLabel ?? events.at(-1)?.label ?? events.at(-1)?.type,
     waitingFor: snapshot.waitingFor,
+    projection: snapshot.projection ?? null,
+    projectionStatus: snapshot.projectionStatus ?? snapshot.projection?.projectionStatus ?? null,
+    projectionHealth: snapshot.projectionHealth ?? snapshot.projection?.projectionHealth ?? null,
+    staleMs: snapshot.staleMs ?? snapshot.projection?.staleMs ?? null,
+    blocker: snapshot.blocker ?? snapshot.projection?.blocker ?? null,
     updatedAt: snapshot.updatedAt ?? new Date().toISOString()
   };
 }
@@ -141,7 +151,12 @@ export function mergeTraceResults(terminal: AgentChatResultResponse, trace: Trac
     terminalEvidence: trace.terminalEvidence ?? terminal.terminalEvidence,
     finalResponse: trace.finalResponse ?? terminal.finalResponse,
     traceSummary: trace.traceSummary ?? terminal.traceSummary,
-    error: trace.error ?? terminal.error
+    error: trace.error ?? terminal.error,
+    projection: trace.projection ?? terminal.projection ?? null,
+    projectionStatus: trace.projectionStatus ?? terminal.projectionStatus ?? null,
+    projectionHealth: trace.projectionHealth ?? terminal.projectionHealth ?? null,
+    staleMs: trace.staleMs ?? terminal.staleMs ?? null,
+    blocker: trace.blocker ?? terminal.blocker ?? null
   };
   const events = Array.isArray(trace.events) ? trace.events : [];
   const assistantText = firstNonEmptyString(finalResponseText(mergedTrace.finalResponse), terminal.assistantText);
@@ -254,6 +269,11 @@ function resultToTraceSnapshot(traceId: string, result: AgentChatResultResponse,
     finalResponse: result.finalResponse,
     traceSummary: result.traceSummary,
     error: result.error,
+    projection: result.projection ?? result.runnerTrace?.projection ?? null,
+    projectionStatus: result.projectionStatus ?? result.runnerTrace?.projectionStatus ?? null,
+    projectionHealth: result.projectionHealth ?? result.runnerTrace?.projectionHealth ?? null,
+    staleMs: result.staleMs ?? result.runnerTrace?.staleMs ?? null,
+    blocker: result.blocker ?? result.runnerTrace?.blocker ?? null,
     lastEventLabel: result.lastEventLabel ?? lastEvent?.label ?? lastEvent?.type,
     eventSource,
     updatedAt: new Date().toISOString()
@@ -288,6 +308,11 @@ function traceSnapshotWithTurnStatus(trace: TraceSnapshot, turn: TraceSnapshot):
     finalResponse: trace.finalResponse ?? turn.finalResponse,
     traceSummary: trace.traceSummary ?? turn.traceSummary,
     error: trace.error ?? turn.error,
+    projection: trace.projection ?? turn.projection ?? null,
+    projectionStatus: trace.projectionStatus ?? turn.projectionStatus ?? null,
+    projectionHealth: trace.projectionHealth ?? turn.projectionHealth ?? null,
+    staleMs: trace.staleMs ?? turn.staleMs ?? null,
+    blocker: trace.blocker ?? turn.blocker ?? null,
     waitingFor: trace.waitingFor ?? turn.waitingFor,
     updatedAt: new Date().toISOString()
   };
@@ -314,7 +339,9 @@ function traceSnapshotSignalKey(snapshot: TraceSnapshot): string {
     snapshot.hasMore === true ? "more" : "caught-up",
     snapshot.fullTraceLoaded === true ? "loaded" : "partial",
     snapshot.lastEventLabel ?? events.at(-1)?.label ?? events.at(-1)?.type ?? "",
-    traceSnapshotErrorKey(snapshot.error)
+    traceSnapshotErrorKey(snapshot.error),
+    snapshot.projectionHealth ?? snapshot.projection?.projectionHealth ?? "",
+    snapshot.projection?.blocker?.code ?? snapshot.blocker?.code ?? ""
   ].join("|");
 }
 
diff --git a/web/hwlab-cloud-web/src/stores/workbench-server-state.ts b/web/hwlab-cloud-web/src/stores/workbench-server-state.ts
index 181e7cd0..5aaf7a1e 100644
--- a/web/hwlab-cloud-web/src/stores/workbench-server-state.ts
+++ b/web/hwlab-cloud-web/src/stores/workbench-server-state.ts
@@ -1,7 +1,7 @@
 // SPEC: PJ2026-010403 API契约 draft-2026-06-18-r1; PJ2026-010401 Web工作台 draft-2026-06-18-r1; PJ2026-0104010803 唯一投影 draft-2026-06-18-p0-unique-projection.
 // Responsibility: Normalized Workbench server-state reducer for session, turn, and trace caches.
 
-import type { ChatMessage, WorkbenchSessionRecord } from "@/types";
+import type { ChatMessage, ProjectionDiagnostic, WorkbenchSessionRecord } from "@/types";
 import type { SessionStatusAuthority, TurnStatusAuthority } from "./workbench-session";
 
 export interface WorkbenchServerState {
@@ -143,10 +143,26 @@ function sessionStatusAuthorityFromDetail(session: WorkbenchSessionRecord): Sess
     status: session.status,
     updatedAt: typeof session.updatedAt === "string" ? session.updatedAt : null,
     lastTraceId: typeof session.lastTraceId === "string" ? session.lastTraceId : null,
+    projection: projectionFromSessionRecord(session),
     loadedAt: new Date().toISOString()
   };
 }
 
+function projectionFromSessionRecord(session: WorkbenchSessionRecord): ProjectionDiagnostic | null {
+  const turnSummary = session.turnSummary && typeof session.turnSummary === "object" ? session.turnSummary as Record<string, unknown> : null;
+  const direct = session.projection && typeof session.projection === "object" ? session.projection : null;
+  const turnProjection = turnSummary?.projection && typeof turnSummary.projection === "object" ? turnSummary.projection as ProjectionDiagnostic : null;
+  if (direct) return direct;
+  if (turnProjection) return turnProjection;
+  const blocker = session.blocker && typeof session.blocker === "object" ? session.blocker : turnSummary?.blocker && typeof turnSummary.blocker === "object" ? turnSummary.blocker : null;
+  if (!session.projectionHealth && !session.projectionStatus && !blocker) return null;
+  return {
+    projectionStatus: typeof session.projectionStatus === "string" ? session.projectionStatus : typeof turnSummary?.projectionStatus === "string" ? turnSummary.projectionStatus : null,
+    projectionHealth: typeof session.projectionHealth === "string" ? session.projectionHealth : typeof turnSummary?.projectionHealth === "string" ? turnSummary.projectionHealth : null,
+    blocker: blocker as ProjectionDiagnostic["blocker"] ?? null
+  };
+}
+
 function withoutKey<T>(source: Record<string, T>, key: string): Record<string, T> {
   if (!(key in source)) return source;
   const next = { ...source };
diff --git a/web/hwlab-cloud-web/src/stores/workbench-session.ts b/web/hwlab-cloud-web/src/stores/workbench-session.ts
index 6a584e9e..ee3ce3f1 100644
--- a/web/hwlab-cloud-web/src/stores/workbench-session.ts
+++ b/web/hwlab-cloud-web/src/stores/workbench-session.ts
@@ -1,7 +1,7 @@
 // SPEC: PJ2026-010403 API契约 draft-2026-06-18-r1; PJ2026-010401 Web工作台 draft-2026-06-18-r1; PJ2026-0104010803 唯一投影 draft-2026-06-18-p0-unique-projection.
 // Responsibility: Session-first Workbench UI helpers for composer state, tab projection, and local list stability.
 
-import type { ChatMessage, ProviderProfile, WorkbenchSessionRecord } from "@/types";
+import type { ChatMessage, ProjectionDiagnostic, ProviderProfile, WorkbenchSessionRecord } from "@/types";
 import { firstNonEmptyString } from "@/utils";
 
 export interface ComposerState {
@@ -20,6 +20,8 @@ export interface SessionTab extends WorkbenchSessionRecord {
   subtitle: string;
   active: boolean;
   running: boolean;
+  projectionHealth?: string | null;
+  projectionDiagnosticText?: string | null;
 }
 
 export interface SessionStatusAuthority {
@@ -27,6 +29,7 @@ export interface SessionStatusAuthority {
   status: string | null;
   updatedAt?: string | null;
   lastTraceId?: string | null;
+  projection?: ProjectionDiagnostic | null;
   loadedAt?: string | null;
 }
 
@@ -40,6 +43,7 @@ export interface TurnStatusAuthority {
   sessionId?: string | null;
   threadId?: string | null;
   updatedAt?: string | null;
+  projection?: ProjectionDiagnostic | null;
   loadedAt?: string | null;
 }
 
@@ -113,6 +117,8 @@ export function sessionToSessionTab(session: WorkbenchSessionRecord, activeSessi
   const sessionId = session.sessionId;
   const updatedAt = sessionDisplayUpdatedAt(session);
   const status = resolveSessionTabStatus(session, sessionStatusAuthority[sessionId]);
+  const projection = projectionFromSession(session, sessionStatusAuthority[sessionId]);
+  const projectionText = projectionDiagnosticText(projection);
   const trace = firstNonEmptyString(latestAgentMessage(session.messages)?.traceId, session.messages?.at(-1)?.traceId, session.lastTraceId);
   const userMessage = session.messages?.find((message) => message.role === "user");
   const running = isRunningIndicatorStatus(status);
@@ -129,11 +135,14 @@ export function sessionToSessionTab(session: WorkbenchSessionRecord, activeSessi
     ...session,
     key: sessionId,
     label: preview ?? `Session ${shortToken(sessionId, 8)}`,
-    subtitle: `${running ? "处理中" : trace ? `trace ${shortToken(trace, 8)}` : status === "unknown" ? "状态同步中" : "未开始"} · ${session.messageCount ?? session.messages?.length ?? 0} 条`,
+    subtitle: `${projectionText ? "状态更新异常" : running ? "处理中" : trace ? `trace ${shortToken(trace, 8)}` : status === "unknown" ? "状态同步中" : "未开始"} · ${session.messageCount ?? session.messages?.length ?? 0} 条`,
     lastTraceId: trace,
     status,
     active: sessionId === activeSessionId,
     running,
+    projection: projection ?? null,
+    projectionHealth: projection?.projectionHealth ?? null,
+    projectionDiagnosticText: projectionText,
     updatedAt
   };
 }
@@ -275,6 +284,28 @@ function resolveSessionTabStatus(session: WorkbenchSessionRecord, authority: Ses
   return authorityStatus ?? "unknown";
 }
 
+function projectionFromSession(session: WorkbenchSessionRecord, authority: SessionStatusAuthority | null | undefined): ProjectionDiagnostic | null {
+  const direct = recordValue(authority?.projection) ?? recordValue(session.projection);
+  if (direct) return direct as ProjectionDiagnostic;
+  const turnSummary = recordValue(session.turnSummary);
+  const turnProjection = recordValue(turnSummary?.projection);
+  if (turnProjection) return turnProjection as ProjectionDiagnostic;
+  const blocker = recordValue(session.blocker) ?? recordValue(turnSummary?.blocker);
+  const projectionHealth = firstNonEmptyString(authority?.projection?.projectionHealth, session.projectionHealth, turnSummary?.projectionHealth);
+  const projectionStatus = firstNonEmptyString(authority?.projection?.projectionStatus, session.projectionStatus, turnSummary?.projectionStatus);
+  if (!projectionHealth && !projectionStatus && !blocker) return null;
+  return { projectionHealth, projectionStatus, blocker } as ProjectionDiagnostic;
+}
+
+function projectionDiagnosticText(projection: ProjectionDiagnostic | null): string | null {
+  if (!projection || projection.projectionHealth === "caught-up") return null;
+  return firstNonEmptyString(projection.blocker?.userMessage, projection.blocker?.message, projection.blocker?.summary, projection.blocker?.code ? `状态更新异常：${projection.blocker.code}` : null);
+}
+
+function recordValue(value: unknown): Record<string, unknown> | null {
+  return value && typeof value === "object" ? value as Record<string, unknown> : null;
+}
+
 function messageBelongsToCancelTarget(message: ChatMessage, input: { targetSessionId?: string | null; targetThreadId?: string | null }): boolean {
   const targetSessionId = firstNonEmptyString(input.targetSessionId);
   const targetThreadId = firstNonEmptyString(input.targetThreadId);
diff --git a/web/hwlab-cloud-web/src/stores/workbench.ts b/web/hwlab-cloud-web/src/stores/workbench.ts
index ced17228..1d80a08f 100644
--- a/web/hwlab-cloud-web/src/stores/workbench.ts
+++ b/web/hwlab-cloud-web/src/stores/workbench.ts
@@ -6,7 +6,7 @@ import { defineStore } from "pinia";
 import { api } from "@/api";
 import { connectWorkbenchEvents, type WorkbenchEventStream, type WorkbenchRealtimeEvent } from "@/api/workbench-events";
 import { mergeRunnerTrace, snapshotToRunnerTrace, type TraceSnapshot } from "@/composables/useTraceSubscription";
-import type { AgentChatResponse, AgentChatResultResponse, AgentRunProvenance, ApiResult, ChatMessage, LiveSurface, ProviderProfile, TraceEvent, WorkbenchSessionRecord } from "@/types";
+import type { AgentChatResponse, AgentChatResultResponse, AgentRunProvenance, ApiResult, ChatMessage, LiveSurface, ProjectionDiagnostic, ProviderProfile, TraceEvent, WorkbenchSessionRecord } from "@/types";
 import { firstNonEmptyString, nextProtocolId, normalizeWorkbenchSessionId, normalizeWorkbenchSessionRouteId } from "@/utils";
 import { failWorkbenchSessionSwitch, failWorkbenchSubmitJourney, finishWorkbenchSessionSwitchFullLoad, markWorkbenchSubmitApiAccepted, markWorkbenchTraceEventsReceived, markWorkbenchTraceProjected, startWorkbenchSessionSwitch, startWorkbenchSubmitJourney } from "@/utils/workbench-performance";
 import { RECENT_DRAFTS_STORAGE_KEY, appendSessionPage, defaultProviderProfileOptions, isArchivedSession, mergeSessionIntoList, normalizeChatMessageStatus, normalizeRecentDrafts, normalizeWorkbenchMessageTitle, providerProfileOptionsFromPayload, recordRecentDraft, resolveCancelableAgentMessage, resolveComposerState, shouldShowSessionListLoading, sortSessionTabs, stableSessionList, type DraftEntry, type ProviderProfileOption, type TurnStatusAuthority } from "./workbench-session";
@@ -347,7 +347,7 @@ export const useWorkbenchStore = defineStore("workbench", () => {
       if (response.data.terminal === true || isTerminalMessageStatus(response.data.status)) completeTrace(id, response.data);
       return;
     }
-    reduceServerState({ type: "turn.forget", traceId: id });
+    applyProjectionDiagnostic(id, projectionDiagnosticFromFailure({ code: "turn_status_poll_failed", message: response.error ?? "状态更新失败，当前 turn 状态暂不可见。", health: response.status === 0 ? "unavailable" : "degraded" }));
   }
 
   function applyTurnStatusSnapshot(traceId: string, result: AgentChatResultResponse | TraceSnapshot): void {
@@ -499,7 +499,10 @@ export const useWorkbenchStore = defineStore("workbench", () => {
       let sinceSeq = traceHydrationSinceSeq(message.runnerTrace);
       for (let page = 0; page < TRACE_HYDRATION_MAX_PAGES; page += 1) {
         const result = await fetchTraceHydrationPage(traceId, sinceSeq);
-        if (!result.ok || !result.data) return;
+        if (!result.ok || !result.data) {
+          applyProjectionDiagnostic(traceId, projectionDiagnosticFromFailure({ code: "trace_hydration_failed", message: result.error ?? "Trace 更新超时，运行记录暂不可见。", health: result.status === 0 ? "unavailable" : "degraded" }));
+          return;
+        }
         applyTraceHydrationResult(traceId, result.data);
         const nextSinceSeq = traceNextSinceSeq(result.data, sinceSeq);
         if (result.data.hasMore !== true || nextSinceSeq <= sinceSeq) return;
@@ -576,6 +579,11 @@ export const useWorkbenchStore = defineStore("workbench", () => {
         finalResponse: result.finalResponse,
         traceSummary: result.traceSummary,
         agentRun: result.agentRun,
+        projection: projectionFromResult(result),
+        projectionStatus: result.projectionStatus ?? result.projection?.projectionStatus,
+        projectionHealth: result.projectionHealth ?? result.projection?.projectionHealth,
+        staleMs: result.staleMs ?? result.projection?.staleMs,
+        blocker: result.blocker ?? result.projection?.blocker,
         lastEventLabel: result.lastEventLabel ?? events.at(-1)?.label ?? events.at(-1)?.type,
         updatedAt: new Date().toISOString()
       });
@@ -584,11 +592,12 @@ export const useWorkbenchStore = defineStore("workbench", () => {
       const status = isTerminalMessageStatus(message.status) ? message.status : resultStatus;
       const terminal = result.terminal === true || isTerminalMessageStatus(status);
       const error = normalizeAgentError(result.error ?? runnerTrace?.error ?? message.error);
+      const projection = projectionFromResult(result) ?? runnerTrace.projection ?? message.projection ?? null;
       const errorText = agentErrorDisplayText(error);
       const text = terminal ? projectedAgentMessageText({ status, finalText: finalResponseText(result.finalResponse), errorText, baseText: message.text }) : message.text;
       const agentRun = agentRunFromResult(result, runnerTrace) ?? agentRunFromMessage(message);
       rememberTraceAuthority(runnerTrace);
-      return { ...message, status, text, runnerTrace, error: error ?? message.error ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
+      return { ...message, status, text, runnerTrace, error: error ?? message.error ?? null, projection, projectionStatus: projection?.projectionStatus ?? null, projectionHealth: projection?.projectionHealth ?? null, blocker: projection?.blocker ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
     }));
     markWorkbenchTraceProjected(traceId);
   }
@@ -735,6 +744,10 @@ export const useWorkbenchStore = defineStore("workbench", () => {
       applyRealtimeTurnSnapshot(event.turn);
       return;
     }
+    if (eventName === "workbench.error" || event.type === "error") {
+      applyRealtimeProjectionError(event);
+      return;
+    }
     if (event.type === "trace.unavailable") {
       const traceId = firstNonEmptyString(event.traceId);
       if (traceId) void clearActiveTrace(traceId, "realtime-trace-unavailable");
@@ -872,7 +885,8 @@ export const useWorkbenchStore = defineStore("workbench", () => {
       const nextText = message.role === "agent" && terminal
         ? projectedAgentMessageText({ status, finalText: finalResponseText(runnerTrace.finalResponse), errorText, baseText: message.text })
         : message.text;
-      return { ...message, status, text: nextText, traceAutoLifecycle: terminal ? "terminal" : message.traceAutoLifecycle, runnerTrace, error: error ?? message.error ?? null, updatedAt: new Date().toISOString() };
+      const projection = trace.projection ?? runnerTrace.projection ?? message.projection ?? null;
+      return { ...message, status, text: nextText, traceAutoLifecycle: terminal ? "terminal" : message.traceAutoLifecycle, runnerTrace, error: error ?? message.error ?? null, projection, projectionStatus: projection?.projectionStatus ?? null, projectionHealth: projection?.projectionHealth ?? null, blocker: projection?.blocker ?? null, updatedAt: new Date().toISOString() };
     }));
     markWorkbenchTraceProjected(traceId);
     void refreshSessions(trace.sessionId ?? selectedSessionId.value);
@@ -889,9 +903,10 @@ export const useWorkbenchStore = defineStore("workbench", () => {
       const runnerTrace = mergeTerminalResultTrace(message.runnerTrace, result);
       rememberTraceAuthority(runnerTrace);
       const error = normalizeAgentError(result.error ?? runnerTrace?.error ?? message.error);
+      const projection = projectionFromResult(result) ?? runnerTrace.projection ?? message.projection ?? null;
       const agentRun = agentRunFromResult(result, runnerTrace) ?? agentRunFromMessage(message);
       const text = projectedAgentMessageText({ status: terminalStatus, finalText, errorText, baseText: message.text });
-      return { ...message, status: terminalStatus, text, traceAutoLifecycle: "terminal", runnerTrace, error: error ?? message.error ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
+      return { ...message, status: terminalStatus, text, traceAutoLifecycle: "terminal", runnerTrace, error: error ?? message.error ?? null, projection, projectionStatus: projection?.projectionStatus ?? null, projectionHealth: projection?.projectionHealth ?? null, blocker: projection?.blocker ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
     }));
     rememberTurnStatus(traceId, result);
     markWorkbenchTraceProjected(traceId);
@@ -925,13 +940,38 @@ export const useWorkbenchStore = defineStore("workbench", () => {
       rememberTraceAuthority(runnerTrace);
       const error = normalizeAgentError(result.error ?? runnerTrace?.error ?? message.error);
       const agentRun = agentRunFromResult(result, runnerTrace) ?? agentRunFromMessage(message);
+      const projection = projectionFromResult(result) ?? runnerTrace.projection ?? message.projection ?? null;
       const status = statusFromResult(result.status);
-      return { ...message, status, title: normalizeWorkbenchMessageTitle(message.role, message.title), runnerTrace, error: error ?? message.error ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
+      return { ...message, status, title: normalizeWorkbenchMessageTitle(message.role, message.title), runnerTrace, error: error ?? message.error ?? null, projection, projectionStatus: projection?.projectionStatus ?? null, projectionHealth: projection?.projectionHealth ?? null, blocker: projection?.blocker ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
     }));
     void hydrateTraceEvents(messages.value);
     void refreshSessions(result.sessionId ?? activeSessionId.value);
   }
 
+  function applyRealtimeProjectionError(event: WorkbenchRealtimeEvent): void {
+    const traceId = firstNonEmptyString(event.traceId, realtimeTraceId());
+    if (!traceId) return;
+    const error = recordValue(event.error) ?? event;
+    applyProjectionDiagnostic(traceId, projectionDiagnosticFromFailure({ code: firstNonEmptyString(error.code, "workbench_realtime_error") ?? "workbench_realtime_error", message: firstNonEmptyString(error.message, error.summary, "Workbench 实时状态更新异常，最新运行记录暂不可见。") ?? "Workbench 实时状态更新异常，最新运行记录暂不可见。", health: "degraded" }));
+  }
+
+  function applyProjectionDiagnostic(traceId: string, projection: ProjectionDiagnostic): void {
+    const message = [...messages.value].reverse().find((item) => shouldApplyTraceToMessage(item, traceId, activeSessionId.value)) ?? null;
+    const sessionId = normalizeWorkbenchSessionId(firstNonEmptyString(message?.sessionId, message?.runnerTrace?.sessionId, activeSessionId.value));
+    const existing = turnStatusAuthority.value[traceId];
+    const status = existing?.status ?? normalizedStatusText(message?.status) ?? null;
+    const running = existing?.running === true || (!isTerminalMessageStatus(message?.status) && isTraceActiveStatus(message?.status));
+    const now = new Date().toISOString();
+    reduceServerState({ type: "turn.status", turn: { traceId, status, running, terminal: existing?.terminal === true, sessionId, threadId: firstNonEmptyString(message?.threadId, message?.runnerTrace?.threadId) ?? existing?.threadId ?? null, updatedAt: now, projection, loadedAt: now } });
+    if (sessionId) reduceServerState({ type: "session.status", session: { sessionId, status: activeSession.value?.status ?? status, updatedAt: now, lastTraceId: traceId, projection, loadedAt: now } });
+    updateActiveMessages((source) => source.map((item) => {
+      if (!shouldApplyTraceToMessage(item, traceId, sessionId)) return item;
+      const runnerTrace = mergeRunnerTrace(item.runnerTrace, { ...(item.runnerTrace ?? {}), traceId, sessionId: sessionId ?? item.runnerTrace?.sessionId, projection, projectionStatus: projection.projectionStatus ?? null, projectionHealth: projection.projectionHealth ?? null, staleMs: projection.staleMs ?? null, blocker: projection.blocker ?? null, events: item.runnerTrace?.events ?? [], eventCount: item.runnerTrace?.eventCount ?? item.runnerTrace?.events?.length ?? 0, eventSource: item.runnerTrace?.eventSource ?? "projection-diagnostic", updatedAt: now });
+      rememberTraceAuthority(runnerTrace);
+      return { ...item, runnerTrace, projection, projectionStatus: projection.projectionStatus ?? null, projectionHealth: projection.projectionHealth ?? null, blocker: projection.blocker ?? null, updatedAt: now };
+    }));
+  }
+
   function failTrace(traceId: string, message: string): void {
     markMessage(traceId, { status: "failed", text: message });
     chatPending.value = false;
@@ -1111,6 +1151,7 @@ function normalizeChatMessage(message: ChatMessage): ChatMessage {
   const role = (message.role as string) === "assistant" ? "agent" : message.role;
   const runnerTrace = normalizeMessageRunnerTrace(message);
   const error = normalizeAgentError(message.error ?? runnerTrace?.error);
+  const projection = projectionFromMessage(message, runnerTrace);
   const agentRun = agentRunFromMessage(message) ?? asAgentRun(runnerTrace?.agentRun);
   const status = normalizeChatMessageStatus(message.status);
   const baseText = firstNonEmptyString(message.text, messageText((message as Record<string, unknown>).content), messageText((message as Record<string, unknown>).message));
@@ -1122,7 +1163,7 @@ function normalizeChatMessage(message: ChatMessage): ChatMessage {
       : ""
     : firstNonEmptyString(baseText, finalText, errorText) ?? "";
   const messageId = firstNonEmptyString((message as Record<string, unknown>).messageId, message.id) ?? nextProtocolId("msg");
-  return { ...message, role, text, id: messageId, messageId, title: normalizeWorkbenchMessageTitle(role, message.title), createdAt: message.createdAt ?? new Date().toISOString(), status, runnerTrace, error: error ?? message.error ?? null, agentRun: agentRun ?? undefined };
+  return { ...message, role, text, id: messageId, messageId, title: normalizeWorkbenchMessageTitle(role, message.title), createdAt: message.createdAt ?? new Date().toISOString(), status, runnerTrace, error: error ?? message.error ?? null, projection, projectionStatus: projection?.projectionStatus ?? null, projectionHealth: projection?.projectionHealth ?? null, blocker: projection?.blocker ?? null, agentRun: agentRun ?? undefined };
 }
 
 function activeTraceIdFromMessages(messages: ChatMessage[], turnStatusAuthority: Record<string, TurnStatusAuthority>): string | null {
@@ -1158,6 +1199,11 @@ function realtimeSnapshotToTraceSnapshot(traceId: string, snapshot: WorkbenchRea
     finalResponse: source.finalResponse,
     traceSummary: source.traceSummary,
     error: normalizeAgentError(source.error) ?? undefined,
+    projection: normalizeProjectionDiagnostic(source.projection ?? source) ?? null,
+    projectionStatus: firstNonEmptyString(source.projectionStatus, recordValue(source.projection)?.projectionStatus) ?? undefined,
+    projectionHealth: firstNonEmptyString(source.projectionHealth, recordValue(source.projection)?.projectionHealth) ?? undefined,
+    staleMs: firstFiniteNumber(source.staleMs, recordValue(source.projection)?.staleMs),
+    blocker: recordValue(source.blocker) ?? recordValue(recordValue(source.projection)?.blocker) ?? undefined,
     lastEventLabel: firstNonEmptyString(source.lastEventLabel, source.lastEvent?.label, source.lastEvent?.type, events.at(-1)?.label, events.at(-1)?.type) ?? undefined,
     eventSource: "trace-api",
     updatedAt: firstNonEmptyString(source.updatedAt) ?? new Date().toISOString()
@@ -1189,6 +1235,11 @@ function mergeTerminalResultTrace(previous: ChatMessage["runnerTrace"], result:
     traceSummary: result.traceSummary ?? resultTrace?.traceSummary ?? previous?.traceSummary,
     agentRun: agentRun ?? undefined,
     error: normalizeAgentError(result.error ?? resultTrace?.error ?? previous?.error) ?? undefined,
+    projection: projectionFromResult(result) ?? normalizeProjectionDiagnostic(resultTrace?.projection ?? resultTrace) ?? previous?.projection ?? null,
+    projectionStatus: result.projectionStatus ?? resultTrace?.projectionStatus ?? previous?.projectionStatus ?? null,
+    projectionHealth: result.projectionHealth ?? resultTrace?.projectionHealth ?? previous?.projectionHealth ?? null,
+    staleMs: result.staleMs ?? resultTrace?.staleMs ?? previous?.staleMs ?? null,
+    blocker: result.blocker ?? resultTrace?.blocker ?? previous?.blocker ?? null,
     runnerKind: firstNonEmptyString(agentRun?.adapter, resultTrace?.runnerKind, previous?.runnerKind) ?? undefined,
     sessionMode: firstNonEmptyString(agentRun?.backendProfile, resultTrace?.sessionMode, previous?.sessionMode) ?? undefined,
     lastEventLabel: firstNonEmptyString(result.lastEventLabel, resultTrace?.lastEventLabel, previous?.lastEventLabel, events.at(-1)?.label, events.at(-1)?.type) ?? undefined,
@@ -1200,7 +1251,8 @@ function normalizeMessageRunnerTrace(message: ChatMessage): ChatMessage["runnerT
   const trace = recordValue(message.runnerTrace);
   const agentRun = agentRunFromMessage(message);
   const error = normalizeAgentError(message.error ?? trace?.error);
-  if (!trace && !agentRun && !error) return message.runnerTrace ?? null;
+  const projection = projectionFromMessage(message, trace as ChatMessage["runnerTrace"] | null);
+  if (!trace && !agentRun && !error && !projection) return message.runnerTrace ?? null;
   return {
     ...(trace ?? {}),
     traceId: message.traceId ?? trace?.traceId,
@@ -1208,11 +1260,44 @@ function normalizeMessageRunnerTrace(message: ChatMessage): ChatMessage["runnerT
     threadId: message.threadId ?? trace?.threadId,
     agentRun: agentRun ?? trace?.agentRun,
     error: error ?? trace?.error,
+    projection,
+    projectionStatus: projection?.projectionStatus ?? trace?.projectionStatus,
+    projectionHealth: projection?.projectionHealth ?? trace?.projectionHealth,
+    staleMs: projection?.staleMs ?? trace?.staleMs,
+    blocker: projection?.blocker ?? trace?.blocker,
     runnerKind: agentRun?.adapter ?? trace?.runnerKind,
     sessionMode: agentRun?.backendProfile ?? trace?.sessionMode
   } as ChatMessage["runnerTrace"];
 }
 
+function projectionFromResult(result: AgentChatResultResponse | TraceSnapshot | Record<string, unknown> | null | undefined): ProjectionDiagnostic | null {
+  return normalizeProjectionDiagnostic(result) ?? normalizeProjectionDiagnostic(recordValue(result)?.runnerTrace) ?? null;
+}
+
+function projectionFromMessage(message: ChatMessage, trace: ChatMessage["runnerTrace"] | null | undefined): ProjectionDiagnostic | null {
+  return normalizeProjectionDiagnostic(message.projection ?? message) ?? normalizeProjectionDiagnostic(trace?.projection ?? trace) ?? null;
+}
+
+function normalizeProjectionDiagnostic(value: unknown): ProjectionDiagnostic | null {
+  const record = recordValue(value);
+  if (!record) return null;
+  const nested = recordValue(record.projection);
+  const source = nested ?? record;
+  const blocker = recordValue(source.blocker ?? record.blocker);
+  const projectionStatus = firstNonEmptyString(source.projectionStatus, record.projectionStatus);
+  const projectionHealth = firstNonEmptyString(source.projectionHealth, record.projectionHealth);
+  const lastProjectedSeq = firstFiniteNumber(source.lastProjectedSeq, record.lastProjectedSeq);
+  const staleMs = firstFiniteNumber(source.staleMs, record.staleMs);
+  const sourceRunId = firstNonEmptyString(source.sourceRunId, record.sourceRunId);
+  const sourceCommandId = firstNonEmptyString(source.sourceCommandId, record.sourceCommandId);
+  if (!projectionStatus && !projectionHealth && !blocker && lastProjectedSeq == null && staleMs == null && !sourceRunId && !sourceCommandId) return null;
+  return { ...source, projectionStatus, projectionHealth, lastProjectedSeq: lastProjectedSeq ?? null, staleMs: staleMs ?? null, sourceRunId: sourceRunId ?? null, sourceCommandId: sourceCommandId ?? null, blocker: blocker as ProjectionDiagnostic["blocker"] ?? null, valuesRedacted: source.valuesRedacted !== false } as ProjectionDiagnostic;
+}
+
+function projectionDiagnosticFromFailure(input: { code: string; message: string; health: string }): ProjectionDiagnostic {
+  return { projectionStatus: "blocked", projectionHealth: input.health, blocker: { code: input.code, message: input.message, category: "workbench-projection", retryable: true }, valuesRedacted: true };
+}
+
 function messageNeedsTerminalDiagnostics(message: ChatMessage): boolean {
   if (message.role !== "agent") return false;
   if (!isTerminalMessageStatus(message.status)) return false;
diff --git a/web/hwlab-cloud-web/src/styles/workbench.css b/web/hwlab-cloud-web/src/styles/workbench.css
index cd5ce77c..f681852d 100644
--- a/web/hwlab-cloud-web/src/styles/workbench.css
+++ b/web/hwlab-cloud-web/src/styles/workbench.css
@@ -698,6 +698,13 @@
   animation: session-tab-running 1100ms linear infinite;
 }
 
+.session-tab[data-projection-health="degraded"],
+.session-tab[data-projection-health="stalled"],
+.session-tab[data-projection-health="unavailable"] {
+  border-color: #f59e0b;
+  background: #fffbeb;
+}
+
 @keyframes session-tab-running {
   from { background-position: 220% 0; }
   to { background-position: -220% 0; }
@@ -720,6 +727,21 @@
   white-space: nowrap;
 }
 
+.session-tab-diagnostic {
+  flex: 0 0 auto;
+  max-width: 88px;
+  border-radius: 4px;
+  background: #fef3c7;
+  padding: 2px 5px;
+  color: #92400e;
+  font-size: 11px;
+  font-weight: 700;
+  line-height: 1.2;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
 .session-tab-time {
   flex: 0 0 auto;
   color: #64748b;
@@ -902,6 +924,15 @@
   padding: 6px 0;
 }
 
+.projection-diagnostic {
+  align-self: flex-start;
+  border: 1px solid #fcd34d;
+  border-radius: 4px;
+  background: #fffbeb;
+  padding: 7px 8px;
+  color: #92400e;
+}
+
 .message-markdown {
   display: grid;
   gap: 8px;
@@ -1189,6 +1220,14 @@
   color: #64748b;
 }
 
+.trace-timeline[data-projection-health="degraded"] .trace-empty,
+.trace-timeline[data-projection-health="stalled"] .trace-empty,
+.trace-timeline[data-projection-health="unavailable"] .trace-empty {
+  border-color: #fcd34d;
+  background: #fffbeb;
+  color: #92400e;
+}
+
 .trace-timeline ol {
   display: grid;
   max-height: 320px;
diff --git a/web/hwlab-cloud-web/src/types/index.ts b/web/hwlab-cloud-web/src/types/index.ts
index 137dbcb0..95edcbbb 100644
--- a/web/hwlab-cloud-web/src/types/index.ts
+++ b/web/hwlab-cloud-web/src/types/index.ts
@@ -91,6 +91,33 @@ export interface CodeAgentAvailability {
   [key: string]: unknown;
 }
 
+export interface ProjectionBlocker {
+  code?: string;
+  message?: string | null;
+  summary?: string | null;
+  userMessage?: string | null;
+  layer?: string | null;
+  category?: string | null;
+  retryable?: boolean | null;
+  runId?: string | null;
+  commandId?: string | null;
+  timeoutMs?: number | null;
+  [key: string]: unknown;
+}
+
+export interface ProjectionDiagnostic {
+  projectionStatus?: string | null;
+  projectionHealth?: "caught-up" | "degraded" | "stalled" | "unavailable" | "unknown" | string | null;
+  lastProjectedSeq?: number | null;
+  sourceRunId?: string | null;
+  sourceCommandId?: string | null;
+  staleMs?: number | null;
+  blocker?: ProjectionBlocker | null;
+  updatedAt?: string | null;
+  valuesRedacted?: boolean;
+  [key: string]: unknown;
+}
+
 export interface WorkbenchSessionRecord {
   sessionId: string;
   threadId?: string | null;
@@ -106,6 +133,11 @@ export interface WorkbenchSessionRecord {
   snapshot?: Record<string, unknown> | null;
   userPreview?: string | null;
   messages?: ChatMessage[];
+  projection?: ProjectionDiagnostic | null;
+  projectionStatus?: string | null;
+  projectionHealth?: string | null;
+  staleMs?: number | null;
+  blocker?: ProjectionBlocker | null;
   [key: string]: unknown;
 }
 
@@ -148,6 +180,11 @@ export interface RunnerTrace {
   range?: { sinceSeq?: number; fromSeq?: number | null; toSeq?: number | null; limit?: number; returned?: number; total?: number; [key: string]: unknown };
   lastEventLabel?: string;
   waitingFor?: string;
+  projection?: ProjectionDiagnostic | null;
+  projectionStatus?: string | null;
+  projectionHealth?: string | null;
+  staleMs?: number | null;
+  blocker?: ProjectionBlocker | null;
   [key: string]: unknown;
 }
 
@@ -169,6 +206,11 @@ export interface ChatMessage {
   traceEvents?: TraceEvent[];
   error?: { code?: string; message?: string; category?: string; providerStatus?: number; [key: string]: unknown } | null;
   traceAutoLifecycle?: "running" | "terminal" | null;
+  projection?: ProjectionDiagnostic | null;
+  projectionStatus?: string | null;
+  projectionHealth?: string | null;
+  staleMs?: number | null;
+  blocker?: ProjectionBlocker | null;
   [key: string]: unknown;
 }
 
@@ -216,6 +258,11 @@ export interface AgentChatResponse {
   lastEventLabel?: string;
   waitingFor?: string;
   error?: string | { code?: string; message?: string; providerStatus?: number; [key: string]: unknown };
+  projection?: ProjectionDiagnostic | null;
+  projectionStatus?: string | null;
+  projectionHealth?: string | null;
+  staleMs?: number | null;
+  blocker?: ProjectionBlocker | null;
   [key: string]: unknown;
 }
 
diff --git a/web/hwlab-cloud-web/tests/workbench-e2e/specs/projection-diagnostics.spec.ts b/web/hwlab-cloud-web/tests/workbench-e2e/specs/projection-diagnostics.spec.ts
new file mode 100644
index 00000000..988466cf
--- /dev/null
+++ b/web/hwlab-cloud-web/tests/workbench-e2e/specs/projection-diagnostics.spec.ts
@@ -0,0 +1,44 @@
+import { expect, gotoWorkbench, saveScreenshot, test } from "../fixtures/test";
+import { selectors, sessionTab } from "../fixtures/selectors";
+
+test.describe("projection diagnostics visibility", () => {
+  test.use({ scenarioId: "projection-degraded-diagnostics" });
+
+  test("turn and trace projection blockers are visible without changing lifecycle", async ({ page }, testInfo) => {
+    await gotoWorkbench(page, "/workbench/sessions/ses_projection_degraded");
+    await expect(page.locator(sessionTab("ses_projection_degraded"))).toHaveAttribute("data-status", "running");
+    await expect(page.locator(sessionTab("ses_projection_degraded"))).toHaveAttribute("data-projection-health", "degraded");
+    const card = page.locator(`${selectors.messageCard}[data-role="agent"][data-status="running"]`).last();
+    await expect(card).toContainText("状态更新超时");
+    await expect(card.locator(selectors.traceTimeline)).toHaveAttribute("data-projection-health", "degraded");
+    await expect(card.locator(".trace-empty")).toContainText("状态更新超时");
+    await expect(page.locator(selectors.commandSend)).toHaveAttribute("data-action", "cancel");
+    await saveScreenshot(page, testInfo, "projection-degraded-visible");
+  });
+});
+
+test.describe("SSE projection errors", () => {
+  test.use({ scenarioId: "projection-sse-error" });
+
+  test("workbench.error binds to the current message diagnostic", async ({ page }, testInfo) => {
+    await gotoWorkbench(page, "/workbench/sessions/ses_projection_sse_error");
+    const card = page.locator(`${selectors.messageCard}[data-role="agent"][data-status="running"]`).last();
+    await expect(card).toContainText("SSE 投影事件异常");
+    await expect(page.locator(sessionTab("ses_projection_sse_error"))).toHaveAttribute("data-projection-health", "degraded");
+    await saveScreenshot(page, testInfo, "projection-sse-error-visible");
+  });
+});
+
+test.describe("REST gap hydration errors", () => {
+  test.use({ scenarioId: "trace-hydration-timeout-diagnostic" });
+
+  test("trace hydration timeout is visible without terminal inference", async ({ page }, testInfo) => {
+    await gotoWorkbench(page, "/workbench/sessions/ses_trace_hydration_timeout");
+    const card = page.locator(`${selectors.messageCard}[data-role="agent"][data-status="running"]`).last();
+    await expect(card).toContainText("Trace 更新超时");
+    await expect(card).toHaveAttribute("data-status", "running");
+    await expect(card.locator(selectors.traceTimeline)).toHaveAttribute("data-projection-health", "degraded");
+    await expect(page.locator(selectors.commandSend)).toHaveAttribute("data-action", "cancel");
+    await saveScreenshot(page, testInfo, "trace-hydration-timeout-visible");
+  });
+});