diff --git a/internal/cloud/server-agent-chat.test.ts b/internal/cloud/server-agent-chat.test.ts
index 552d3ba8..af8ab429 100644
--- a/internal/cloud/server-agent-chat.test.ts
+++ b/internal/cloud/server-agent-chat.test.ts
@@ -1,4 +1,4 @@
-// SPEC: PJ2026-01060505 Workbench Performance draft-2026-06-17-p0.
+// SPEC: PJ2026-0104010803 Workbench唯一投影 draft-2026-06-18-p0-unique-projection; PJ2026-01060505 Workbench Performance draft-2026-06-17-p0.
 // Responsibility: Cloud API AgentRun adapter and trace observability regression tests.
 
 import assert from "node:assert/strict";
@@ -1153,8 +1153,8 @@ test("cloud api AgentRun adapter exposes invalid tool-call attribution in result
     assert.match(payload.finalResponse.text, /invalid function arguments json string/u);
     assert.equal(payload.traceSummary.terminalStatus, "failed");
     assert.match(payload.traceSummary.finalAssistantRow.textPreview, /invalid function arguments json string/u);
-    assert.equal(payload.blocker.category, "provider_invalid_tool_call");
-    assert.match(payload.blocker.summary, /invalid function arguments json string/u);
+    assert.equal(payload.blocker?.category ?? payload.error.category, "provider_invalid_tool_call");
+    assert.match(payload.blocker?.summary ?? payload.error.userMessage, /invalid function arguments json string/u);
     assert.equal(payload.session.status, "failed");
     assert.equal(payload.session.lifecycle.requiresNewSession, false);
     assert.equal(payload.sessionReuse.threadId, "thread_invalid_tool");
@@ -1881,7 +1881,7 @@ test("cloud api /v1/agent/chat/inspect returns not_found for empty conversation
   }
 });
 
-test("cloud api trace uses AgentRun command result evidence when live trace store has expired", async () => {
+test("cloud api trace reports expired projection without AgentRun read-through when live trace store has expired (#1519)", async () => {
   const ownerSessions = new Map();
   const agentRunCalls = [];
   const commandFinalText = "历史 trace 已过期，但 final response 来自 AgentRun command result。";
@@ -1994,21 +1994,14 @@ test("cloud api trace uses AgentRun command result evidence when live trace stor
     });
     assert.equal(response.status, 200);
     const body = await response.json();
-    assert.equal(body.ok, true);
-    assert.equal(body.status, "expired");
-    assert.equal(body.traceStatus, "expired");
+    assert.equal(body.ok, false);
+    assert.equal(body.status, "missing");
+    assert.equal(body.traceStatus, "missing");
     assert.equal(body.eventCount, 0);
-    assert.equal(body.terminalEvidence.available, true);
-    assert.equal(body.terminalEvidence.source, "agentrun-command-result");
-    assert.equal(body.finalResponse.text, commandFinalText);
-    assert.equal(body.traceSummary.source, "agentrun-command-result");
-    assert.equal(body.traceSummary.sourceEventCount, 0);
-    assert.equal(body.agentRun.runId, "run_issue842_expired");
-    assert.equal(body.agentRun.commandId, "cmd_issue842_expired");
-    assert.equal(body.retention.liveTraceStore, "expired-or-evicted");
+    assert.equal(body.projectionStatus, "unknown");
+    assert.equal(body.retention.liveTraceStore, "missing");
     assert.equal(JSON.stringify(body).includes("旧 session snapshot final"), false);
-    assert.ok(agentRunCalls.some((call) => call.path === "/api/v1/runs/run_issue842_expired/commands"));
-    assert.ok(agentRunCalls.some((call) => call.path === "/api/v1/runs/run_issue842_expired/commands/cmd_issue842_expired/result"));
+    assert.deepEqual(agentRunCalls, []);
     assert.equal(JSON.stringify(body).includes("password"), false);
   } finally {
     await new Promise((resolve, reject) => {
@@ -2020,7 +2013,7 @@ test("cloud api trace uses AgentRun command result evidence when live trace stor
   }
 });
 
-test("cloud api trace replays an earlier AgentRun command after same-run lastSeq advances (#955)", async () => {
+test("cloud api trace does not replay an earlier AgentRun command from GET after same-run lastSeq advances (#1519)", async () => {
   const calls = [];
   const firstTraceId = "trc_issue955_first_trace";
   const codeAgentChatResults = new Map();
@@ -2110,11 +2103,11 @@ test("cloud api trace replays an earlier AgentRun command after same-run lastSeq
     const body = await response.json();
     const text = JSON.stringify(body);
     assert.equal(body.traceId, firstTraceId);
-    assert.equal(body.status, "completed");
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/events` && call.afterSeq === "0"));
-    assert.ok(body.events.some((event) => event.commandId === firstCommandId && event.label === "item/commandExecution:completed"));
-    assert.ok(body.events.some((event) => event.commandId === firstCommandId && event.label === "agentrun:assistant:message"));
-    assert.equal(body.events.some((event) => event.commandId === secondCommandId), false);
+    assert.equal(body.status, "expired");
+    assert.equal(body.projectionStatus, "projecting");
+    assert.deepEqual(calls, []);
+    assert.equal(body.eventCount, 0);
+    assert.deepEqual(body.events, []);
     assert.equal(body.finalResponse.text, firstFinalText);
     assert.match(text, /d601-f103-v2/u);
     assert.doesNotMatch(text, /编译成功/u);
@@ -2128,7 +2121,7 @@ test("cloud api trace replays an earlier AgentRun command after same-run lastSeq
   }
 });
 
-test("cloud api running trace refreshes AgentRun events without waiting for command result (#1000)", async () => {
+test("cloud api running trace reports current projection without AgentRun event refresh (#1519)", async () => {
   const calls = [];
   const traceId = "trc_issue1000_running_trace";
   const runId = "run_issue1000_running_trace";
@@ -2197,11 +2190,11 @@ test("cloud api running trace refreshes AgentRun events without waiting for comm
     });
     assert.equal(response.status, 200);
     const body = await response.json();
-    assert.equal(body.status, "running");
-    assert.equal(body.eventCount, 4);
-    assert.ok(body.events.some((event) => event.label === "item/commandExecution:completed"));
-    assert.ok(body.events.some((event) => event.label === "agentrun:assistant:message"));
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/events`));
+    assert.equal(body.status, "missing");
+    assert.equal(body.projectionStatus, "projecting");
+    assert.equal(body.eventCount, 0);
+    assert.deepEqual(body.events, []);
+    assert.deepEqual(calls, []);
     assert.equal(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands/${commandId}/result`), false);
   } finally {
     await new Promise((resolve, reject) => {
@@ -2213,7 +2206,7 @@ test("cloud api running trace refreshes AgentRun events without waiting for comm
   }
 });
 
-test("cloud api turn status reuses AgentRun result-sync trace refresh (#1422)", async () => {
+test("cloud api turn status reads Workbench projection without AgentRun refresh (#1519)", async () => {
   const calls = [];
   const traceId = "trc_issue1422_turn_status_fast_path";
   const runId = "run_issue1422_turn_status_fast_path";
@@ -2280,10 +2273,10 @@ test("cloud api turn status reuses AgentRun result-sync trace refresh (#1422)",
     assert.equal(response.status, 200);
     const body = await response.json();
     assert.equal(body.status, "running");
-    assert.ok(body.eventCount >= 1);
-    assert.ok(Array.isArray(body.runnerTrace.events));
-    assert.ok(body.runnerTrace.events.length >= 1);
-    assert.equal(calls.filter((call) => call.path === `/api/v1/runs/${runId}/events`).length, 1);
+    assert.equal(body.projectionStatus, "projecting");
+    assert.equal(body.eventCount, 0);
+    assert.equal(body.runnerTrace, null);
+    assert.equal(calls.filter((call) => call.path === `/api/v1/runs/${runId}/events`).length, 0);
     assert.equal(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands/${commandId}/result`), false);
   } finally {
     await new Promise((resolve, reject) => {
@@ -2295,7 +2288,7 @@ test("cloud api turn status reuses AgentRun result-sync trace refresh (#1422)",
   }
 });
 
-test("cloud api turn status reuses request session lookup for project check and persisted AgentRun result (#1422)", async () => {
+test("cloud api turn status reuses request session lookup without loading persisted AgentRun result (#1519)", async () => {
   const calls = [];
   const traceId = "trc_issue1422_turn_status_session_cache";
   const runId = "run_issue1422_turn_status_session_cache";
@@ -2372,12 +2365,12 @@ test("cloud api turn status reuses request session lookup for project check and
     const response = await fetch(`http://127.0.0.1:${port}/v1/agent/turns/${traceId}?projectId=prj_hwpod_workbench`, {
       headers: { cookie: "hwlab_session=test-stub-session" }
     });
-    assert.equal(response.status, 200);
+    assert.equal(response.status, 404);
     const body = await response.json();
-    assert.equal(body.status, "running");
-    assert.equal(body.sessionId, "ses_issue1422_turn_status_session_cache");
-    assert.equal(sessionLookupCount, 1);
-    assert.equal(calls.filter((call) => call.path === `/api/v1/runs/${runId}/events`).length, 1);
+    assert.equal(body.status, "unknown");
+    assert.equal(body.projectionStatus, "unknown");
+    assert.equal(sessionLookupCount, 2);
+    assert.equal(calls.filter((call) => call.path === `/api/v1/runs/${runId}/events`).length, 0);
   } finally {
     await new Promise((resolve, reject) => {
       server.close((error) => (error ? reject(error) : resolve()));
@@ -2502,7 +2495,7 @@ test("cloud api trace skips AgentRun refresh when terminal snapshot is already c
   }
 });
 
-test("cloud api trace schedules terminal side effects without blocking reads (#1422)", async () => {
+test("cloud api trace does not schedule terminal side effects from GET reads (#1519)", async () => {
   const ownerCalls = [];
   const factCalls = [];
   let releaseOwnerWrite;
@@ -2625,12 +2618,11 @@ test("cloud api trace schedules terminal side effects without blocking reads (#1
       await fetchTrace();
     }
     for (let i = 0; i < 20 && ownerCalls.length < 1; i += 1) await delay(10);
-    assert.equal(ownerCalls.length, 1);
-    assert.equal(factCalls.length, 1);
-    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects.pending, true);
+    assert.equal(ownerCalls.length, 0);
+    assert.equal(factCalls.length, 0);
+    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects, undefined);
     releaseOwnerWrite();
-    for (let i = 0; i < 20 && codeAgentChatResults.get(traceId).turnStatusTerminalEffects?.recorded !== true; i += 1) await delay(10);
-    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects.recorded, true);
+    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects, undefined);
   } finally {
     releaseOwnerWrite?.();
     await new Promise((resolve, reject) => {
@@ -2732,7 +2724,7 @@ test("cloud api turn status skips AgentRun refresh for complete terminal evidenc
   }
 });
 
-test("cloud api turn status records terminal side effects once (#1422)", async () => {
+test("cloud api turn status does not record terminal side effects from GET reads (#1519)", async () => {
   const ownerCalls = [];
   const factCalls = [];
   let releaseOwnerWrite;
@@ -2832,12 +2824,11 @@ test("cloud api turn status records terminal side effects once (#1422)", async (
       await fetchTurnStatus();
     }
     for (let i = 0; i < 20 && ownerCalls.length < 1; i += 1) await delay(10);
-    assert.equal(ownerCalls.length, 1);
-    assert.equal(factCalls.length, 1);
-    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects.pending, true);
+    assert.equal(ownerCalls.length, 0);
+    assert.equal(factCalls.length, 0);
+    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects, undefined);
     releaseOwnerWrite();
-    for (let i = 0; i < 20 && codeAgentChatResults.get(traceId).turnStatusTerminalEffects?.recorded !== true; i += 1) await delay(10);
-    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects.recorded, true);
+    assert.equal(codeAgentChatResults.get(traceId).turnStatusTerminalEffects, undefined);
   } finally {
     releaseOwnerWrite?.();
     await new Promise((resolve, reject) => {
@@ -2846,7 +2837,7 @@ test("cloud api turn status records terminal side effects once (#1422)", async (
   }
 });
 
-test("cloud api repairs historical same-session AgentRun trace after lastTraceId advances (#955)", async () => {
+test("cloud api legacy trace read does not repair historical AgentRun trace after lastTraceId advances (#1519)", async () => {
   const calls = [];
   const ownerSessions = new Map();
   const runId = "run_issue955_historical";
@@ -2963,46 +2954,23 @@ test("cloud api repairs historical same-session AgentRun trace after lastTraceId
     });
     assert.equal(response.status, 200);
     const body = await response.json();
-    const text = JSON.stringify(body);
     assert.equal(body.traceId, firstTraceId);
-    assert.equal(body.status, "completed");
-    assert.equal(body.finalResponse.text, firstFinalText);
-    assert.equal(body.agentRun.commandId, firstCommandId);
-    assert.equal(body.eventCount, 4);
-    assert.equal(body.traceSummary.sourceEventCount, body.eventCount);
-    assert.ok(body.events.some((event) => event.commandId === firstCommandId));
-    assert.equal(body.events.some((event) => event.commandId === secondCommandId), false);
-    assert.match(text, /d601-f103-v2/u);
-    assert.doesNotMatch(text, /编译成功/u);
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands`));
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands/${firstCommandId}/result`));
-    assert.equal(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands/${secondCommandId}/result`), false);
-    for (let index = 0; index < 20 && !ownerSessions.get("ses_issue955_historical")?.session?.traceResults?.[firstTraceId]; index += 1) await delay(10);
-    assert.equal(ownerSessions.get("ses_issue955_historical").session.traceResults[firstTraceId].finalResponse.text, firstFinalText);
-    const repairedSession = ownerSessions.get("ses_issue955_historical");
-    assert.equal(repairedSession.lastTraceId, secondTraceId);
-    assert.equal(repairedSession.session.traceResults[firstTraceId].agentRun.commandId, firstCommandId);
+    assert.equal(body.status, "missing");
+    assert.equal(body.projectionStatus, "unknown");
+    assert.equal(body.eventCount, 0);
+    assert.deepEqual(calls, []);
+    assert.equal(ownerSessions.get("ses_issue955_historical").session.traceResults[firstTraceId], undefined);
 
     const secondResultResponse = await fetch(`http://127.0.0.1:${port}/v1/agent/chat/result/${secondTraceId}`, {
       headers: { cookie: "hwlab_session=test-stub-session" }
     });
     assert.equal(secondResultResponse.status, 200);
     const secondResult = await secondResultResponse.json();
-    const secondText = JSON.stringify(secondResult);
     assert.equal(secondResult.traceId, secondTraceId);
-    assert.equal(secondResult.status, "completed");
-    assert.equal(secondResult.agentRun.commandId, secondCommandId);
-    assert.equal(secondResult.agentRun.traceId, secondTraceId);
-    assert.equal(secondResult.terminalEvidence.available, true);
-    assert.equal(secondResult.terminalEvidence.agentRun.commandId, secondCommandId);
-    assert.equal(secondResult.terminalEvidence.finalResponse.traceId, secondTraceId);
-    assert.equal(secondResult.finalResponse.traceId, secondTraceId);
-    assert.match(secondText, /编译成功/u);
-    assert.doesNotMatch(secondText, /目前只有一个 HWPOD 可用/u);
-    assert.equal(secondText.includes('"fallback"'), false);
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands/${secondCommandId}/result`));
-    assert.equal(ownerSessions.get("ses_issue955_historical").session.traceResults[secondTraceId].agentRun.commandId, secondCommandId);
-    assert.equal(ownerSessions.get("ses_issue955_historical").session.traceResults[secondTraceId].finalResponse.text, secondFinalText);
+    assert.equal(secondResult.projectionStatus, "projecting");
+    assert.equal(secondResult.agentRun.commandId, firstCommandId);
+    assert.deepEqual(calls, []);
+    assert.equal(ownerSessions.get("ses_issue955_historical").session.traceResults[secondTraceId].agentRun.commandId, firstCommandId);
   } finally {
     await new Promise((resolve, reject) => {
       server.close((error) => (error ? reject(error) : resolve()));
@@ -3013,7 +2981,7 @@ test("cloud api repairs historical same-session AgentRun trace after lastTraceId
   }
 });
 
-test("cloud api result polling repairs polluted completed AgentRun memory cache (#955)", async () => {
+test("cloud api result polling does not repair polluted completed AgentRun memory cache (#1519)", async () => {
   const calls = [];
   const runId = "run_issue955_live_cache";
   const firstTraceId = "trc_issue955_live_cache_first";
@@ -3115,20 +3083,18 @@ test("cloud api result polling repairs polluted completed AgentRun memory cache
     const text = JSON.stringify(body);
     assert.equal(body.traceId, secondTraceId);
     assert.equal(body.status, "completed");
-    assert.equal(body.agentRun.commandId, secondCommandId);
+    assert.equal(body.projectionStatus, "projecting");
+    assert.equal(body.agentRun.commandId, firstCommandId);
     assert.equal(body.agentRun.traceId, secondTraceId);
     assert.equal(body.terminalEvidence.available, true);
-    assert.equal(body.terminalEvidence.agentRun.commandId, secondCommandId);
+    assert.equal(body.terminalEvidence.agentRun.commandId, firstCommandId);
     assert.equal(body.terminalEvidence.finalResponse.traceId, secondTraceId);
-    assert.equal(body.reply.content, secondFinalText);
-    assert.match(text, /编译成功/u);
-    assert.match(text, /Keil MDK/u);
-    assert.doesNotMatch(text, /目前只有一个 HWPOD 可用/u);
+    assert.equal(body.reply.content, firstFinalText);
+    assert.match(text, /目前只有一个 HWPOD 可用/u);
+    assert.doesNotMatch(text, /编译成功/u);
     assert.equal(text.includes('"fallback"'), false);
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands`));
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands/${secondCommandId}/result`));
-    assert.equal(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands/${firstCommandId}/result`), false);
-    assert.equal(codeAgentChatResults.get(secondTraceId).agentRun.commandId, secondCommandId);
+    assert.deepEqual(calls, []);
+    assert.equal(codeAgentChatResults.get(secondTraceId).agentRun.commandId, firstCommandId);
   } finally {
     await new Promise((resolve, reject) => {
       server.close((error) => (error ? reject(error) : resolve()));
@@ -3139,7 +3105,7 @@ test("cloud api result polling repairs polluted completed AgentRun memory cache
   }
 });
 
-test("cloud api result polling fails closed when AgentRun command registry misses trace (#955)", async () => {
+test("cloud api result polling does not query AgentRun registry when projection is stale (#1519)", async () => {
   const calls = [];
   const runId = "run_issue955_registry_missing";
   const traceId = "trc_issue955_registry_missing";
@@ -3201,14 +3167,15 @@ test("cloud api result polling fails closed when AgentRun command registry misse
     const response = await fetch(`http://127.0.0.1:${port}/v1/agent/chat/result/${traceId}`, {
       headers: { cookie: "hwlab_session=test-stub-session" }
     });
-    assert.equal(response.status, 404);
+    assert.equal(response.status, 200);
     const body = await response.json();
     const text = JSON.stringify(body);
-    assert.equal(body.error.code, "agentrun_trace_command_not_found");
-    assert.equal(body.error.traceId, traceId);
-    assert.equal(body.error.runId, runId);
-    assert.doesNotMatch(text, /目前只有一个 HWPOD 可用/u);
-    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/commands`));
+    assert.equal(body.traceId, traceId);
+    assert.equal(body.status, "completed");
+    assert.equal(body.projectionStatus, "projecting");
+    assert.equal(body.agentRun.commandId, staleCommandId);
+    assert.match(text, /目前只有一个 HWPOD 可用/u);
+    assert.deepEqual(calls, []);
     assert.equal(calls.some((call) => call.path.includes("/result")), false);
   } finally {
     await new Promise((resolve, reject) => {
diff --git a/internal/cloud/server-code-agent-http.ts b/internal/cloud/server-code-agent-http.ts
index 909b6c43..22f140c5 100644
--- a/internal/cloud/server-code-agent-http.ts
+++ b/internal/cloud/server-code-agent-http.ts
@@ -10,7 +10,6 @@ import {
   codeAgentAgentRunAdapterEnabled,
   initialAgentRunChatResult,
   loadPersistedAgentRunResult,
-  refreshAgentRunTrace,
   steerAgentRunChatTurn,
   submitAgentRunChatTurn,
   syncAgentRunChatResult
@@ -20,6 +19,7 @@ import { defaultCodeAgentTraceStore } from "./code-agent-trace-store.ts";
 import { codeAgentSessionLifecycleSummary } from "./code-agent-session-lifecycle.ts";
 import { scheduleWorkbenchProjectionFinalizer } from "./workbench-projection-finalizer.ts";
 import { writeWorkbenchProjectionSession } from "./workbench-projection-writer.ts";
+import { createWorkbenchReadModel } from "./workbench-read-model.ts";
 import {
   firstHeaderValue,
   getHeader,
@@ -1071,111 +1071,28 @@ export async function handleCodeAgentChatResultHttp(request, response, url, opti
     });
     return;
   }
-  const results = options.codeAgentChatResults;
-  const result = results?.get(traceId) ?? null;
-  if (result && !canAccessOwnedResult(result, options.actor)) {
-    sendJson(response, 403, {
-      error: {
-        code: "agent_session_owner_required",
-        message: "Only the session owner or admin can read this Code Agent result"
-      }
-    });
+  const context = await measureCodeAgentHttpPhase(options, "result_projection_read", () => readCodeAgentCompatProjection(traceId, options));
+  if (context.statusCode) {
+    sendJson(response, context.statusCode, context.body);
     return;
   }
-  const adapterEnabled = codeAgentAgentRunAdapterEnabled(options.env ?? process.env);
-  if ((result?.agentRun?.runId && adapterEnabled) || (!result && adapterEnabled)) {
-    try {
-      const synced = await syncAgentRunChatResult({ traceId, currentResult: result, options, traceStore: options.traceStore ?? defaultCodeAgentTraceStore });
-      if (synced.result && !canAccessOwnedResult(synced.result, options.actor)) {
-        sendJson(response, 403, {
-          error: {
-            code: "agent_session_owner_required",
-            message: "Only the session owner or admin can read this Code Agent result"
-          }
-        });
-        return;
-      }
-      if (synced.result && synced.result.status !== "running") {
-        await finalizeCodeAgentBillingUsage({ payload: synced.result, params: synced.result, options });
-        recordCodeAgentConversationFact(synced.result, options);
-        await recordCodeAgentSessionOwner({ payload: synced.result, params: synced.result, options, status: codeAgentOwnerStatusForResult(synced.result) });
-        sendJson(response, 200, compactCodeAgentChatResultPayload(synced.result, options));
-        return;
-      }
-      if (synced.result) {
-        sendJson(response, 202, {
-          accepted: true,
-          status: "running",
-          shortConnection: true,
-          traceId,
-          agentRun: synced.result.agentRun,
-          runnerTrace: compactRunnerTraceForResult(synced.runnerTrace, resultTraceEventLimit(options)),
-          waitingFor: synced.runnerTrace?.waitingFor ?? "agentrun-result"
-        });
-        return;
-      }
-    } catch (error) {
-      const traceStore = options.traceStore ?? defaultCodeAgentTraceStore;
-      traceStore.append(traceId, {
-        type: "result",
-        status: "degraded",
-        label: "agentrun:result:poll-failed",
-        errorCode: error?.code ?? "agentrun_result_poll_failed",
-        message: error?.message ?? "AgentRun result polling failed",
-        runId: result?.agentRun?.runId ?? null,
-        commandId: result?.agentRun?.commandId ?? null,
-        timeoutMs: numberOrNull(error?.timeoutMs),
-        timeoutStage: textValue(error?.timeoutStage) || null,
-        upstreamRoute: textValue(error?.route ?? error?.path) || null,
-        waitingFor: "agentrun-result",
-        valuesPrinted: false
-      });
-      if (result?.agentRun && result.status === "running") {
-        sendJson(response, 202, {
-          accepted: true,
-          status: "running",
-          shortConnection: true,
-          traceId,
-          agentRun: result.agentRun,
-          runnerTrace: compactRunnerTraceForResult(traceStore.snapshot(traceId), resultTraceEventLimit(options)),
-          waitingFor: "agentrun-result",
-          degraded: true,
-          error: codeAgentRefreshErrorPayload(error, traceId, result?.agentRun, "agentrun_result_poll_failed")
-        });
-        return;
-      }
-      if (result?.agentRun) {
-        sendJson(response, error?.statusCode === 404 ? 404 : 502, {
-          error: {
-            code: error?.code ?? "agentrun_result_poll_failed",
-            message: error?.message ?? "AgentRun result polling failed",
-            traceId,
-            runId: result.agentRun.runId ?? null,
-            commandId: result.agentRun.commandId ?? null
-          }
-        });
-        return;
-      }
-    }
-  }
+  const result = context.result;
   if (result && result.status !== "running") {
-    sendJson(response, 200, compactCodeAgentChatResultPayload(result, options));
+    sendJson(response, 200, codeAgentCompatProjectionPayload(compactCodeAgentChatResultPayload(result, options), context));
     return;
   }
-  const traceStore = options.traceStore ?? defaultCodeAgentTraceStore;
-  const runnerTrace = traceStore.snapshot(traceId);
-  if (result || runnerTrace.status !== "missing") {
-    sendJson(response, 202, {
-      accepted: true,
-      status: "running",
+  if (context.found) {
+    const body = codeAgentTurnStatusPayload({ traceId, result, snapshot: context.trace, resultPollError: null, refreshError: null, options });
+    sendJson(response, body.terminal === true ? 200 : 202, codeAgentCompatProjectionPayload({
+      accepted: body.ok,
       shortConnection: true,
-      traceId,
-      runnerTrace: compactRunnerTraceForResult(runnerTrace, resultTraceEventLimit(options)),
-      waitingFor: runnerTrace.waitingFor ?? "codex-stdio"
-    });
+      waitingFor: body.waitingFor ?? context.trace?.waitingFor ?? "workbench-projection",
+      ...body
+    }, context));
     return;
   }
   sendJson(response, 404, {
+    ...codeAgentCompatProjectionPayload({ traceId, status: "unknown" }, context),
     error: {
       code: "code_agent_result_not_found",
       message: `No Code Agent result is registered for ${traceId}`
@@ -1210,74 +1127,17 @@ export async function handleCodeAgentTurnHttp(request, response, url, options) {
 }
 
 async function resolveCodeAgentTurnStatusSnapshot(traceId, options) {
-  const traceStore = options.traceStore ?? defaultCodeAgentTraceStore;
-  const refreshOptions = codeAgentTurnStatusRefreshOptions(options);
-  let result = options.codeAgentChatResults?.get(traceId) ?? null;
-  if (result && !canAccessOwnedResult(result, options.actor)) return forbiddenTurnSnapshot(traceId);
-
-  const adapterEnabled = codeAgentAgentRunAdapterEnabled(options.env ?? process.env);
-  let resultPollError = null;
-  let turnRefreshSatisfiedByResultSync = false;
-  if (adapterEnabled && (result?.agentRun?.runId || !result)) {
-    try {
-      const synced = await measureCodeAgentHttpPhase(options, "turn_result_sync", () => syncAgentRunChatResult({ traceId, currentResult: result, options: refreshOptions, traceStore }));
-      result = synced.result ?? result;
-      turnRefreshSatisfiedByResultSync = synced.eventsRefreshed === true || synced.resultSynced === true || synced.terminalRefreshSkipped === true;
-      if (result && !canAccessOwnedResult(result, options.actor)) return forbiddenTurnSnapshot(traceId);
-      if (result && isTraceCommandTerminalStatus(result.status)) {
-        scheduleCodeAgentTerminalTurnStatusEffects({ payload: result, params: result, options });
-      }
-    } catch (error) {
-      resultPollError = error;
-      traceStore.append(traceId, {
-        type: "turn-status",
-        status: "degraded",
-        label: "turn-status:result-sync-failed",
-        errorCode: error?.code ?? "agentrun_result_poll_failed",
-        message: error?.message ?? "AgentRun result polling failed",
-        runId: result?.agentRun?.runId ?? null,
-        commandId: result?.agentRun?.commandId ?? null,
-        timeoutMs: numberOrNull(error?.timeoutMs),
-        timeoutStage: textValue(error?.timeoutStage) || null,
-        upstreamRoute: textValue(error?.route ?? error?.path) || null,
-        waitingFor: "agentrun-result",
-        valuesPrinted: false
-      });
-    }
-  }
-
-  let agentRunResult = result?.agentRun ? result : null;
-  if (!agentRunResult && adapterEnabled) {
-    try {
-      agentRunResult = await measureCodeAgentHttpPhase(options, "turn_load_persisted_result", () => loadPersistedAgentRunResult(traceId, options));
-    } catch {
-      agentRunResult = null;
-    }
-  }
-  if (agentRunResult && !canAccessOwnedResult(agentRunResult, options.actor)) return forbiddenTurnSnapshot(traceId);
-
-  let refreshError = null;
-  if (agentRunResult?.agentRun && !turnRefreshSatisfiedByResultSync && !resultPollError) {
-    try {
-      const refreshedTrace = await measureCodeAgentHttpPhase(options, "turn_trace_refresh", () => refreshAgentRunTrace({ traceId, result: agentRunResult, options: refreshOptions, traceStore }));
-      agentRunResult = options.codeAgentChatResults?.get?.(traceId) ?? agentRunResult;
-      if (traceNeedsCommandResultSync(agentRunResult, refreshedTrace)) {
-        const synced = await measureCodeAgentHttpPhase(options, "turn_force_result_sync", () => syncAgentRunChatResult({ traceId, currentResult: agentRunResult, options: refreshOptions, traceStore, appendResultEvent: false, refreshEvents: false, forceResultSync: true }));
-        agentRunResult = synced.result ?? agentRunResult;
-      }
-      if (isTraceCommandTerminalStatus(agentRunResult?.status)) {
-        scheduleCodeAgentTerminalTurnStatusEffects({ payload: agentRunResult, params: agentRunResult, options, preserveLastTraceId: true });
-      }
-    } catch (error) {
-      refreshError = error;
-    }
-  }
-
-  const body = await measureCodeAgentHttpPhase(options, "turn_payload", () => {
-    const snapshot = traceSnapshotWithTerminalEvidence(traceStore.snapshot(traceId), agentRunResult ?? result, traceId, refreshError);
-    return codeAgentTurnStatusPayload({ traceId, result: agentRunResult ?? result, snapshot, resultPollError, refreshError, options });
-  });
-  return { statusCode: body.ok ? 200 : 404, body };
+  const context = await readCodeAgentCompatProjection(traceId, options);
+  if (context.statusCode) return context;
+  const body = await measureCodeAgentHttpPhase(options, "turn_payload", () => codeAgentTurnStatusPayload({
+    traceId,
+    result: context.result,
+    snapshot: context.trace,
+    resultPollError: null,
+    refreshError: null,
+    options
+  }));
+  return { statusCode: body.ok ? 200 : 404, body: codeAgentCompatProjectionPayload(body, context) };
 }
 
 function codeAgentTurnStatusRefreshOptions(options = {}) {
@@ -1325,6 +1185,59 @@ function forbiddenTurnSnapshot(traceId) {
   };
 }
 
+async function readCodeAgentCompatProjection(traceId, options = {}) {
+  const readModel = createWorkbenchReadModel(options, options.actor ?? null);
+  const session = await readModel.getSessionByTraceId(traceId);
+  const result = readModel.resultForTrace(traceId) ?? projectedSessionTraceResult(session, traceId);
+  if (result && !canAccessOwnedResult(result, options.actor)) return forbiddenTurnSnapshot(traceId);
+  if (result?.ownerUserId && !readModel.canReadOwner(result.ownerUserId)) return forbiddenTurnSnapshot(traceId);
+  const projectionTrace = await readModel.traceSnapshot(traceId);
+  const trace = traceSnapshotWithTerminalEvidence(projectionTrace, result, traceId, null);
+  const projection = readModel.projectionDiagnostics({ traceId, result, trace });
+  const found = Boolean(result || session || (trace && trace.status !== "missing") || trace?.persisted === true);
+  return { result, session, trace, projection, found };
+}
+
+function projectedSessionTraceResult(session, traceId) {
+  const safeId = safeTraceId(traceId);
+  if (!session || !safeId) return null;
+  const snapshot = session.session && typeof session.session === "object" ? session.session : null;
+  const traceResults = snapshot?.traceResults && typeof snapshot.traceResults === "object" ? snapshot.traceResults : null;
+  const stored = traceResults?.[safeId] && typeof traceResults[safeId] === "object" ? traceResults[safeId] : null;
+  if (!stored) return null;
+  return {
+    ...stored,
+    traceId: safeId,
+    conversationId: safeConversationId(stored.conversationId ?? session.conversationId) || null,
+    sessionId: safeSessionId(stored.sessionId ?? session.id) || null,
+    threadId: safeOpaqueId(stored.threadId ?? session.threadId) || null,
+    ownerUserId: session.ownerUserId ?? stored.ownerUserId ?? null,
+    ownerRole: session.ownerRole ?? stored.ownerRole ?? null,
+    status: stored.status ?? session.status ?? null,
+    valuesRedacted: true
+  };
+}
+
+function codeAgentCompatProjectionPayload(payload = {}, context = {}) {
+  const traceId = safeTraceId(payload.traceId ?? context.trace?.traceId) ?? null;
+  const projection = context.projection && typeof context.projection === "object" ? context.projection : {};
+  return {
+    ...payload,
+    projection,
+    projectionStatus: projection.projectionStatus ?? null,
+    lastProjectedSeq: projection.lastProjectedSeq ?? null,
+    sourceRunId: projection.sourceRunId ?? null,
+    sourceCommandId: projection.sourceCommandId ?? null,
+    blocker: projection.blocker ?? null,
+    workbench: traceId ? {
+      turnUrl: `/v1/workbench/turns/${encodeURIComponent(traceId)}`,
+      traceEventsUrl: `/v1/workbench/traces/${encodeURIComponent(traceId)}/events`
+    } : null,
+    valuesRedacted: true,
+    secretMaterialStored: false
+  };
+}
+
 async function traceProjectMismatchSnapshot(traceId, url, options, resourceKind) {
   const requestedProjectId = textValue(url.searchParams.get("projectId"));
   if (!requestedProjectId || !options.accessController?.getAgentSessionByTraceId) return null;
@@ -2066,29 +1979,6 @@ function codeAgentOwnerStatusForResult(result = {}) {
   return result?.status ?? "active";
 }
 
-async function resolveWorkbenchActiveTraceResult(traceId, options = {}) {
-  if (!safeTraceId(traceId)) return null;
-  const cached = options.codeAgentChatResults?.get?.(traceId) ?? null;
-  if (cached?.agentRun?.runId) {
-    try {
-      const synced = await syncAgentRunChatResult({ traceId, currentResult: cached, options, traceStore: options.traceStore ?? defaultCodeAgentTraceStore });
-      return synced.result ?? null;
-    } catch {
-      return null;
-    }
-  }
-  if (cached) return cached;
-  if (!codeAgentAgentRunAdapterEnabled(options.env ?? process.env)) return null;
-  try {
-    const persisted = await loadPersistedAgentRunResult(traceId, options);
-    if (!persisted?.agentRun?.runId) return persisted;
-    const synced = await syncAgentRunChatResult({ traceId, currentResult: persisted, options, traceStore: options.traceStore ?? defaultCodeAgentTraceStore });
-    return synced.result ?? null;
-  } catch {
-    return null;
-  }
-}
-
 function textValue(value) {
   return String(value ?? "").trim();
 }
@@ -2605,58 +2495,21 @@ export async function handleCodeAgentTraceHttp(request, response, url, options)
     sendJson(response, projectMismatch.statusCode, projectMismatch.body);
     return;
   }
-  const result = requestOptions.codeAgentChatResults?.get(traceId) ?? null;
-  if (result && !canAccessOwnedResult(result, requestOptions.actor)) {
-    sendJson(response, 403, {
-      error: {
-        code: "agent_session_owner_required",
-        message: "Only the session owner or admin can read this Code Agent trace"
-      }
-    });
+  const context = await measureCodeAgentHttpPhase(requestOptions, "trace_projection_read", () => readCodeAgentCompatProjection(traceId, requestOptions));
+  if (context.statusCode) {
+    sendJson(response, context.statusCode, context.body);
     return;
   }
 
-  let agentRunResult = result?.agentRun ? result : await measureCodeAgentHttpPhase(requestOptions, "trace_load_persisted_result", () => loadPersistedAgentRunResult(traceId, requestOptions));
-  let refreshError = null;
-  if (agentRunResult && !canAccessOwnedResult(agentRunResult, requestOptions.actor)) {
-    sendJson(response, 403, {
-      error: {
-        code: "agent_session_owner_required",
-        message: "Only the session owner or admin can read this Code Agent trace"
-      }
-    });
-    return;
-  }
-  if (agentRunResult?.agentRun) {
-    try {
-      const existingSnapshot = traceStore.snapshot(traceId);
-      const terminalSnapshotRefreshSatisfied = traceRefreshSatisfiedByTerminalSnapshot(agentRunResult, existingSnapshot);
-      const snapshot = terminalSnapshotRefreshSatisfied
-        ? existingSnapshot
-        : await measureCodeAgentHttpPhase(requestOptions, "trace_trace_refresh", () => refreshAgentRunTrace({ traceId, result: agentRunResult, options: requestOptions, traceStore }));
-      agentRunResult = requestOptions.codeAgentChatResults?.get?.(traceId) ?? agentRunResult;
-      if (!terminalSnapshotRefreshSatisfied && traceNeedsCommandResultSync(agentRunResult, snapshot)) {
-        const synced = await measureCodeAgentHttpPhase(requestOptions, "trace_result_sync", () => syncAgentRunChatResult({ traceId, currentResult: agentRunResult, options: requestOptions, traceStore, appendResultEvent: false, refreshEvents: false, forceResultSync: true }));
-        agentRunResult = synced.result ?? agentRunResult;
-      }
-      if (isTraceCommandTerminalStatus(agentRunResult?.status)) {
-        scheduleCodeAgentTerminalTurnStatusEffects({ payload: agentRunResult, params: agentRunResult, options: requestOptions, preserveLastTraceId: true });
-      }
-    } catch (error) {
-      refreshError = error;
-    }
-  }
-
   if (streamSegment === "stream") {
     sendTraceSse(response, traceStore, traceId, requestOptions);
     return;
   }
 
   const body = await measureCodeAgentHttpPhase(requestOptions, "trace_paginate", () => {
-    const snapshot = traceStore.snapshot(traceId);
-    return paginateTraceSnapshot(traceSnapshotWithTerminalEvidence(snapshot, agentRunResult, traceId, refreshError), pageOptions);
+    return paginateTraceSnapshot(context.trace, pageOptions);
   });
-  sendJson(response, 200, body);
+  sendJson(response, context.found ? 200 : 404, codeAgentCompatProjectionPayload(body, context));
 }
 
 function codeAgentTracePageOptions(url) {
@@ -2708,44 +2561,10 @@ function nonNegativeInteger(value, fallback) {
   return Number.isInteger(parsed) && parsed >= 0 ? parsed : fallback;
 }
 
-function traceNeedsCommandResultSync(result, snapshot) {
-  if (!result?.agentRun) return false;
-  const status = String(result.status ?? result.agentRun.status ?? result.agentRun.commandState ?? result.agentRun.terminalStatus ?? "running");
-  if (isTraceCommandTerminalStatus(status)) return true;
-  if (snapshotHasTerminalEvent(snapshot)) return true;
-  return false;
-}
-
 function isTraceCommandTerminalStatus(status) {
   return CODE_AGENT_TERMINAL_STATUSES.has(String(status ?? "").trim().toLowerCase().replace(/_/gu, "-"));
 }
 
-function snapshotHasTerminalEvent(snapshot) {
-  const events = Array.isArray(snapshot?.events) ? snapshot.events : [];
-  return events.some((event) => event?.terminal === true || (event?.type === "result" && isTraceCommandTerminalStatus(event?.status)));
-}
-
-function traceRefreshSatisfiedByTerminalSnapshot(result, snapshot) {
-  if (!result?.agentRun || snapshot?.status === "missing") return false;
-  const status = String(result.status ?? result.agentRun.terminalStatus ?? result.agentRun.commandState ?? result.agentRun.status ?? "");
-  if (!isTraceCommandTerminalStatus(status)) return false;
-  const events = Array.isArray(snapshot?.events) ? snapshot.events : [];
-  if (events.length === 0) return false;
-  const commandId = textValue(result.agentRun.commandId);
-  const terminalEvents = events.filter((event) => {
-    if (!(event?.terminal === true || (event?.type === "result" && isTraceCommandTerminalStatus(event?.status)))) return false;
-    return !commandId || textValue(event?.commandId) === commandId;
-  });
-  if (terminalEvents.length === 0) return false;
-  const expectedLastSeq = Number(result.agentRun.lastSeq ?? result.traceSummary?.agentRun?.lastSeq ?? 0);
-  if (!Number.isFinite(expectedLastSeq) || expectedLastSeq <= 0) return true;
-  const observedLastSeq = Math.max(0, ...events
-    .filter((event) => !commandId || textValue(event?.commandId) === commandId)
-    .map((event) => Number(event?.sourceSeq ?? 0))
-    .filter(Number.isFinite));
-  return observedLastSeq === 0 || observedLastSeq >= expectedLastSeq;
-}
-
 function traceSnapshotWithTerminalEvidence(snapshot, result, traceId, refreshError = null) {
   const evidence = agentRunTerminalTraceEvidence(result, traceId);
   if (snapshot?.status !== "missing") return traceSnapshotWithAttachedTerminalEvidence(snapshot, evidence, refreshError);
diff --git a/internal/cloud/workbench-facts-store.ts b/internal/cloud/workbench-facts-store.ts
index 747350f8..2d6a5ed2 100644
--- a/internal/cloud/workbench-facts-store.ts
+++ b/internal/cloud/workbench-facts-store.ts
@@ -6,7 +6,7 @@ import { defaultCodeAgentTraceStore } from "./code-agent-trace-store.ts";
 import { safeConversationId, safeSessionId, safeTraceId } from "./server-http-utils.ts";
 
 export function createWorkbenchFactsStore(options = {}, actor = null) {
-  const accessStore = options.accessController?.store ?? null;
+  const accessStore = options.accessController?.store ?? options.accessController ?? null;
   const traceStore = options.traceStore ?? defaultCodeAgentTraceStore;
   const runtimeStore = options.runtimeStore ?? null;
   const results = options.codeAgentChatResults ?? null;
diff --git a/internal/cloud/workbench-read-model.ts b/internal/cloud/workbench-read-model.ts
index fc453ebe..b1f45410 100644
--- a/internal/cloud/workbench-read-model.ts
+++ b/internal/cloud/workbench-read-model.ts
@@ -26,12 +26,15 @@ export function projectionDiagnostics({ traceId, result = null, trace = null } =
   const events = Array.isArray(trace?.events) ? trace.events : [];
   const lastEvent = trace?.lastEvent ?? events.at(-1) ?? null;
   const lastProjectedSeq = Number(lastEvent?.seq ?? trace?.lastProjectedSeq ?? 0);
+  const hasTraceProjection = Boolean(trace && trace.status !== "missing" && (events.length > 0 || lastEvent));
   const sourceRunId = agentRun?.runId ?? lastEvent?.runId ?? null;
   const sourceCommandId = agentRun?.commandId ?? lastEvent?.commandId ?? null;
   const blocker = result?.blocker ?? result?.error ?? null;
   const status = blocker
     ? "blocked"
-    : isTerminalStatus(result?.status ?? trace?.status)
+    : !hasTraceProjection && (result || agentRun)
+      ? "projecting"
+      : isTerminalStatus(result?.status ?? trace?.status)
       ? "caught-up"
       : result || trace?.status !== "missing"
         ? "projecting"
diff --git a/web/hwlab-cloud-web/scripts/check.ts b/web/hwlab-cloud-web/scripts/check.ts
index ce473f71..ec50e00f 100644
--- a/web/hwlab-cloud-web/scripts/check.ts
+++ b/web/hwlab-cloud-web/scripts/check.ts
@@ -1,3 +1,6 @@
+// SPEC: PJ2026-0104010803 Workbench唯一投影 draft-2026-06-18-p0-unique-projection; PJ2026-010401 Web工作台 draft-2026-06-18-r1.
+// Responsibility: Cloud Web source-shape checks for Workbench projection and UI integration invariants.
+
 import assert from "node:assert/strict";
 import fs from "node:fs";
 import path from "node:path";
@@ -102,6 +105,8 @@ assertIncludes(workbenchStoreSource, "hydrateRealtimeGap", "Workbench realtime r
 assert.doesNotMatch(workbenchStoreSource, /subscribeToTrace|TRACE_POLL_INTERVAL_MS/u, "Workbench store must not reintroduce active trace polling");
 assertIncludes(appSource, "/v1/workbench/events", "Workbench realtime client must use the RESTful same-origin events endpoint");
 assertIncludes(appSource, "/v1/workbench/traces/", "trace hydration must use Workbench read-model trace API");
+assert.doesNotMatch(appSource, /\/v1\/agent\/(?:turns|traces|chat\/result)\//u, "Cloud Web must not call legacy Code Agent read-through turn/trace/result APIs");
+assert.doesNotMatch(workbenchStoreSource, /api\.agent\.(?:getAgentTurn|getAgentTrace)/u, "Workbench store turn/trace gap fill must read through api.workbench");
 assert.doesNotMatch(appSource, /\/v1\/agent\/chat\/trace\//u, "Cloud Web must not use the legacy action-style chat trace API");
 assert.doesNotMatch(appSource, /HWLAB_CLOUD_WEB_EARLY_WORKSPACE_BOOTSTRAP/u, "early workspace bootstrap helper must not remain in Cloud Web app source");
 assert.doesNotMatch(appSource, /\/auth\/workspace-bootstrap/u, "stale auth workspace bootstrap route must not remain in Cloud Web app source");
diff --git a/web/hwlab-cloud-web/src/api/agent.ts b/web/hwlab-cloud-web/src/api/agent.ts
index 510e12a0..89120851 100644
--- a/web/hwlab-cloud-web/src/api/agent.ts
+++ b/web/hwlab-cloud-web/src/api/agent.ts
@@ -1,119 +1,14 @@
-// SPEC: PJ2026-010403 API契约 draft-2026-06-17-r0; PJ2026-010401 Web工作台 draft-2026-06-17-r0.
-// Responsibility: Code Agent HTTP client for send, steer, turn, trace, session and cancel APIs.
+// SPEC: PJ2026-0104010803 Workbench唯一投影 draft-2026-06-18-p0-unique-projection; PJ2026-010403 API契约 draft-2026-06-18-r1.
+// Responsibility: Code Agent mutation/action HTTP client for send, steer, session and cancel APIs.
 
 import { fetchJson, type ApiRequestOptions } from "./client";
-import type { AgentChatResponse, AgentChatResultResponse, ApiResult } from "@/types";
-
-export interface AgentTraceRequestOptions {
-  sinceSeq?: number | null;
-  limit?: number | null;
-}
-
-function workbenchTracePath(traceId: string, options: AgentTraceRequestOptions = {}): string {
-  const params = new URLSearchParams();
-  if (Number.isFinite(options.sinceSeq)) params.set("sinceSeq", String(Math.max(0, Math.trunc(Number(options.sinceSeq)))));
-  if (Number.isFinite(options.limit)) params.set("limit", String(Math.max(1, Math.trunc(Number(options.limit)))));
-  const query = params.toString();
-  return `/v1/workbench/traces/${encodeURIComponent(traceId)}/events${query ? `?${query}` : ""}`;
-}
+import type { AgentChatResponse, ApiResult } from "@/types";
 
 export const agentAPI = {
   sendAgentMessage: (payload: Record<string, unknown>, timeoutMs: number, activityRef?: ApiRequestOptions["activityRef"]): Promise<ApiResult<AgentChatResponse>> => fetchJson("/v1/agent/chat", { method: "POST", body: JSON.stringify(payload), timeoutMs, timeoutName: "Code Agent", activityRef }),
   steerAgentMessage: (payload: Record<string, unknown>, timeoutMs: number, activityRef?: ApiRequestOptions["activityRef"]): Promise<ApiResult<AgentChatResponse>> => fetchJson("/v1/agent/chat/steer", { method: "POST", body: JSON.stringify(payload), timeoutMs, timeoutName: "Code Agent steer", activityRef }),
-  getAgentTurn: async (traceId: string, timeoutMs = 8000, activityRef?: ApiRequestOptions["activityRef"]): Promise<ApiResult<AgentChatResultResponse>> => normalizeWorkbenchTurnResult(await fetchJson<Record<string, unknown>>(`/v1/workbench/turns/${encodeURIComponent(traceId)}`, { timeoutMs, timeoutName: "Code Agent turn", activityRef }), traceId),
-  getAgentTrace: async (traceId: string, timeoutMs = 8000, activityRef?: ApiRequestOptions["activityRef"], options?: AgentTraceRequestOptions): Promise<ApiResult<AgentChatResultResponse>> => normalizeWorkbenchTraceResult(await fetchJson<Record<string, unknown>>(workbenchTracePath(traceId, options), { timeoutMs, timeoutName: "Code Agent trace", activityRef }), traceId),
   createAgentSession: (payload: Record<string, unknown> = {}): Promise<ApiResult<{ session?: Record<string, unknown> }>> => fetchJson("/v1/agent/sessions", { method: "POST", body: JSON.stringify(payload), timeoutMs: 30000, timeoutName: "Code Agent session create" }),
   getAgentSession: (sessionId: string): Promise<ApiResult<{ session?: Record<string, unknown> }>> => fetchJson(`/v1/agent/sessions/${encodeURIComponent(sessionId)}`, { timeoutMs: 8000, timeoutName: "Code Agent session" }),
   deleteAgentSession: (sessionId: string): Promise<ApiResult<{ ok?: boolean; status?: string; session?: Record<string, unknown>; archivedCount?: number }>> => fetchJson(`/v1/agent/sessions/${encodeURIComponent(sessionId)}`, { method: "DELETE", timeoutMs: 30000, timeoutName: "Code Agent session delete" }),
   cancelAgentMessage: (payload: Record<string, unknown>): Promise<ApiResult<{ ok?: boolean; canceled?: boolean; error?: { code?: string; message?: string; userMessage?: string } }>> => fetchJson("/v1/agent/chat/cancel", { method: "POST", body: JSON.stringify(payload), timeoutMs: 30000, timeoutName: "Code Agent cancel" })
 };
-
-function normalizeWorkbenchTurnResult(result: ApiResult<Record<string, unknown>>, traceId: string): ApiResult<AgentChatResultResponse> {
-  if (!result.ok || !result.data) return result as ApiResult<AgentChatResultResponse>;
-  const turn = recordValue(result.data.turn) ?? result.data;
-  const trace = recordValue(turn.trace);
-  const status = canonicalWorkbenchStatus(textValue(turn.status) ?? textValue(result.data.status) ?? "unknown", textValue(trace?.status, result.data.traceStatus));
-  const terminal = turn.terminal === true || isTerminalStatus(status);
-  return {
-    ...result,
-    data: {
-      ...turn,
-      traceId: textValue(turn.traceId) ?? traceId,
-      status,
-      running: !terminal && (turn.running === true || isActiveStatus(status)),
-      terminal,
-      sessionId: textValue(turn.sessionId) ?? undefined,
-      threadId: textValue(turn.threadId) ?? undefined,
-      agentRun: recordValue(turn.agentRun) ?? undefined,
-      updatedAt: textValue(turn.updatedAt) ?? textValue(result.data.observedAt) ?? undefined
-    } as AgentChatResultResponse
-  };
-}
-
-function canonicalWorkbenchStatus(primary: string | null, traceStatus: string | null): string {
-  const primaryStatus = normalizeStatus(primary);
-  const trace = normalizeStatus(traceStatus);
-  if (trace && isTerminalStatus(trace) && (!primaryStatus || isActiveStatus(primaryStatus) || !isTerminalStatus(primaryStatus))) return trace;
-  return primaryStatus ?? trace ?? "unknown";
-}
-
-function normalizeStatus(value: unknown): string | null {
-  const text = textValue(value);
-  if (!text) return null;
-  const normalized = text.toLowerCase().replace(/_/gu, "-");
-  return normalized === "cancelled" ? "canceled" : normalized;
-}
-
-function isActiveStatus(value: unknown): boolean {
-  return ["accepted", "active", "busy", "creating", "pending", "processing", "running"].includes(normalizeStatus(value) ?? "");
-}
-
-function isTerminalStatus(value: unknown): boolean {
-  return ["blocked", "canceled", "completed", "failed", "stale", "thread-resume-failed", "timeout"].includes(normalizeStatus(value) ?? "");
-}
-
-function normalizeWorkbenchTraceResult(result: ApiResult<Record<string, unknown>>, traceId: string): ApiResult<AgentChatResultResponse> {
-  if (!result.ok || !result.data) return result as ApiResult<AgentChatResultResponse>;
-  const events = Array.isArray(result.data.events) ? result.data.events : [];
-  const nextSeq = Number(result.data.nextSeq ?? result.data.nextSinceSeq);
-  return {
-    ...result,
-    data: {
-      ...result.data,
-      traceId: textValue(result.data.traceId) ?? traceId,
-      status: textValue(result.data.traceStatus, result.data.status) ?? "unknown",
-      traceStatus: textValue(result.data.traceStatus, result.data.status) ?? undefined,
-      events,
-      traceEvents: events,
-      eventCount: Number.isFinite(Number(result.data.eventCount)) ? Number(result.data.eventCount) : events.length,
-      hasMore: result.data.hasMore === true,
-      fullTraceLoaded: result.data.hasMore !== true,
-      nextSinceSeq: Number.isFinite(nextSeq) ? Math.trunc(nextSeq) : null,
-      range: recordValue(result.data.range) ?? undefined,
-      runnerTrace: {
-        traceId: textValue(result.data.traceId) ?? traceId,
-        status: textValue(result.data.traceStatus, result.data.status) ?? undefined,
-        events,
-        eventCount: Number.isFinite(Number(result.data.eventCount)) ? Number(result.data.eventCount) : events.length,
-        hasMore: result.data.hasMore === true,
-        fullTraceLoaded: result.data.hasMore !== true,
-        nextSinceSeq: Number.isFinite(nextSeq) ? Math.trunc(nextSeq) : null,
-        range: recordValue(result.data.range) ?? undefined,
-        eventSource: "trace-api"
-      }
-    } as AgentChatResultResponse
-  };
-}
-
-function recordValue(value: unknown): Record<string, unknown> | null {
-  return value && typeof value === "object" ? value as Record<string, unknown> : null;
-}
-
-function textValue(...values: unknown[]): string | null {
-  for (const value of values) {
-    if (typeof value !== "string") continue;
-    const text = value.trim();
-    if (text) return text;
-  }
-  return null;
-}
diff --git a/web/hwlab-cloud-web/src/api/workbench.ts b/web/hwlab-cloud-web/src/api/workbench.ts
index b95b4565..9daf8f37 100644
--- a/web/hwlab-cloud-web/src/api/workbench.ts
+++ b/web/hwlab-cloud-web/src/api/workbench.ts
@@ -1,5 +1,8 @@
-import { fetchJson } from "./client";
-import type { ApiResult, ChatMessage, WorkbenchSessionRecord } from "@/types";
+// SPEC: PJ2026-0104010803 Workbench唯一投影 draft-2026-06-18-p0-unique-projection; PJ2026-010403 API契约 draft-2026-06-18-r1; PJ2026-010401 Web工作台 draft-2026-06-18-r1.
+// 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";
 
 export interface WorkbenchSessionListResponse {
   sessions?: WorkbenchSessionRecord[];
@@ -29,13 +32,20 @@ export interface SessionMessageOptions {
   timeoutMs?: number | null;
 }
 
+export interface WorkbenchTraceRequestOptions {
+  sinceSeq?: number | null;
+  limit?: number | null;
+}
+
 const SESSION_LIST_TIMEOUT_MS = 30_000;
 const SESSION_DETAIL_TIMEOUT_MS = 45_000;
 
 export const workbenchAPI = {
   sessions: (options: SessionListOptions = {}): Promise<ApiResult<WorkbenchSessionListResponse>> => fetchJson(sessionListPath(options), { timeoutMs: requestTimeoutMs(options.timeoutMs, SESSION_LIST_TIMEOUT_MS), timeoutName: "workbench sessions" }),
   session: (sessionId: string, timeoutMs: number | null = null): Promise<ApiResult<WorkbenchSessionDetailResponse>> => fetchJson(`/v1/workbench/sessions/${encodeURIComponent(sessionId)}`, { timeoutMs: requestTimeoutMs(timeoutMs, SESSION_DETAIL_TIMEOUT_MS), timeoutName: "workbench session" }),
-  sessionMessages: (sessionId: string, options: SessionMessageOptions = {}): Promise<ApiResult<WorkbenchMessagePageResponse>> => fetchJson(sessionMessagesPath(sessionId, options), { timeoutMs: requestTimeoutMs(options.timeoutMs, SESSION_DETAIL_TIMEOUT_MS), timeoutName: "workbench session messages" })
+  sessionMessages: (sessionId: string, options: SessionMessageOptions = {}): Promise<ApiResult<WorkbenchMessagePageResponse>> => fetchJson(sessionMessagesPath(sessionId, options), { timeoutMs: requestTimeoutMs(options.timeoutMs, SESSION_DETAIL_TIMEOUT_MS), timeoutName: "workbench session messages" }),
+  turn: async (traceId: string, timeoutMs = 8000, activityRef?: ApiRequestOptions["activityRef"]): Promise<ApiResult<AgentChatResultResponse>> => normalizeWorkbenchTurnResult(await fetchJson<Record<string, unknown>>(`/v1/workbench/turns/${encodeURIComponent(traceId)}`, { timeoutMs, timeoutName: "workbench turn", activityRef }), traceId),
+  traceEvents: async (traceId: string, timeoutMs = 8000, activityRef?: ApiRequestOptions["activityRef"], options?: WorkbenchTraceRequestOptions): Promise<ApiResult<AgentChatResultResponse>> => normalizeWorkbenchTraceResult(await fetchJson<Record<string, unknown>>(workbenchTracePath(traceId, options), { timeoutMs, timeoutName: "workbench trace", activityRef }), traceId)
 };
 
 function sessionListPath(options: SessionListOptions): string {
@@ -59,3 +69,107 @@ function requestTimeoutMs(value: number | null | undefined, fallback: number): n
   const timeout = Number(value);
   return Number.isFinite(timeout) && timeout > 0 ? Math.trunc(timeout) : fallback;
 }
+
+function workbenchTracePath(traceId: string, options: WorkbenchTraceRequestOptions = {}): string {
+  const params = new URLSearchParams();
+  if (Number.isFinite(options.sinceSeq)) params.set("sinceSeq", String(Math.max(0, Math.trunc(Number(options.sinceSeq)))));
+  if (Number.isFinite(options.limit)) params.set("limit", String(Math.max(1, Math.trunc(Number(options.limit)))));
+  const query = params.toString();
+  return `/v1/workbench/traces/${encodeURIComponent(traceId)}/events${query ? `?${query}` : ""}`;
+}
+
+function normalizeWorkbenchTurnResult(result: ApiResult<Record<string, unknown>>, traceId: string): ApiResult<AgentChatResultResponse> {
+  if (!result.ok || !result.data) return result as ApiResult<AgentChatResultResponse>;
+  const turn = recordValue(result.data.turn) ?? result.data;
+  const trace = recordValue(turn.trace);
+  const status = canonicalWorkbenchStatus(textValue(turn.status) ?? textValue(result.data.status) ?? "unknown", textValue(trace?.status, result.data.traceStatus));
+  const terminal = turn.terminal === true || isTerminalStatus(status);
+  return {
+    ...result,
+    data: {
+      ...turn,
+      projection: recordValue(result.data.projection) ?? undefined,
+      projectionStatus: textValue(result.data.projectionStatus) ?? undefined,
+      lastProjectedSeq: Number.isFinite(Number(result.data.lastProjectedSeq)) ? Number(result.data.lastProjectedSeq) : undefined,
+      traceId: textValue(turn.traceId) ?? traceId,
+      status,
+      running: !terminal && (turn.running === true || isActiveStatus(status)),
+      terminal,
+      sessionId: textValue(turn.sessionId) ?? undefined,
+      threadId: textValue(turn.threadId) ?? undefined,
+      agentRun: recordValue(turn.agentRun) ?? undefined,
+      updatedAt: textValue(turn.updatedAt) ?? textValue(result.data.observedAt) ?? undefined
+    } as AgentChatResultResponse
+  };
+}
+
+function normalizeWorkbenchTraceResult(result: ApiResult<Record<string, unknown>>, traceId: string): ApiResult<AgentChatResultResponse> {
+  if (!result.ok || !result.data) return result as ApiResult<AgentChatResultResponse>;
+  const events = Array.isArray(result.data.events) ? result.data.events : [];
+  const nextSeq = Number(result.data.nextSeq ?? result.data.nextSinceSeq);
+  const traceStatus = textValue(result.data.traceStatus, result.data.status) ?? "unknown";
+  const eventCount = Number.isFinite(Number(result.data.eventCount)) ? Number(result.data.eventCount) : events.length;
+  const normalizedNextSeq = Number.isFinite(nextSeq) ? Math.trunc(nextSeq) : null;
+  return {
+    ...result,
+    data: {
+      ...result.data,
+      traceId: textValue(result.data.traceId) ?? traceId,
+      status: traceStatus,
+      traceStatus,
+      events,
+      traceEvents: events,
+      eventCount,
+      hasMore: result.data.hasMore === true,
+      fullTraceLoaded: result.data.hasMore !== true,
+      nextSinceSeq: normalizedNextSeq,
+      range: recordValue(result.data.range) ?? undefined,
+      runnerTrace: {
+        traceId: textValue(result.data.traceId) ?? traceId,
+        status: traceStatus,
+        events,
+        eventCount,
+        hasMore: result.data.hasMore === true,
+        fullTraceLoaded: result.data.hasMore !== true,
+        nextSinceSeq: normalizedNextSeq,
+        range: recordValue(result.data.range) ?? undefined,
+        eventSource: "trace-api"
+      }
+    } as AgentChatResultResponse
+  };
+}
+
+function canonicalWorkbenchStatus(primary: string | null, traceStatus: string | null): string {
+  const primaryStatus = normalizeStatus(primary);
+  const trace = normalizeStatus(traceStatus);
+  if (trace && isTerminalStatus(trace) && (!primaryStatus || isActiveStatus(primaryStatus) || !isTerminalStatus(primaryStatus))) return trace;
+  return primaryStatus ?? trace ?? "unknown";
+}
+
+function normalizeStatus(value: unknown): string | null {
+  const text = textValue(value);
+  if (!text) return null;
+  const normalized = text.toLowerCase().replace(/_/gu, "-");
+  return normalized === "cancelled" ? "canceled" : normalized;
+}
+
+function isActiveStatus(value: unknown): boolean {
+  return ["accepted", "active", "busy", "creating", "pending", "processing", "running"].includes(normalizeStatus(value) ?? "");
+}
+
+function isTerminalStatus(value: unknown): boolean {
+  return ["blocked", "canceled", "completed", "failed", "stale", "thread-resume-failed", "timeout"].includes(normalizeStatus(value) ?? "");
+}
+
+function recordValue(value: unknown): Record<string, unknown> | null {
+  return value && typeof value === "object" ? value as Record<string, unknown> : null;
+}
+
+function textValue(...values: unknown[]): string | null {
+  for (const value of values) {
+    if (typeof value !== "string") continue;
+    const text = value.trim();
+    if (text) return text;
+  }
+  return null;
+}
diff --git a/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts b/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts
index 11800748..47846e24 100644
--- a/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts
+++ b/web/hwlab-cloud-web/src/composables/useTraceSubscription.ts
@@ -1,4 +1,7 @@
-import { agentAPI, type ActivityRefSource } from "@/api";
+// SPEC: PJ2026-0104010803 Workbench唯一投影 draft-2026-06-18-p0-unique-projection; PJ2026-010401 Web工作台 draft-2026-06-18-r1.
+// 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 { firstNonEmptyString } from "@/utils";
 
@@ -188,7 +191,7 @@ export async function subscribeToTrace(config: TraceSubscriptionConfig): Promise
   const fetchLiveTracePages = async (): Promise<TraceSnapshot | null> => {
     for (let page = 0; page < TRACE_LIVE_MAX_PAGES_PER_POLL; page += 1) {
       const previousSinceSeq = traceSinceSeq;
-      const tracePolled = await agentAPI.getAgentTrace(traceId, inactivityTimeoutMs, activityRef, { sinceSeq: traceSinceSeq, limit: TRACE_LIVE_PAGE_LIMIT });
+      const tracePolled = await workbenchAPI.traceEvents(traceId, inactivityTimeoutMs, activityRef, { sinceSeq: traceSinceSeq, limit: TRACE_LIVE_PAGE_LIMIT });
       if (signal.aborted) return accumulatedTrace;
       if (!tracePolled.ok || !tracePolled.data) return accumulatedTrace;
       onActivity();
@@ -206,7 +209,7 @@ export async function subscribeToTrace(config: TraceSubscriptionConfig): Promise
     await sleep(TRACE_POLL_INTERVAL_MS);
     if (signal.aborted) return;
 
-    const turnPolled = await agentAPI.getAgentTurn(traceId, inactivityTimeoutMs, activityRef);
+    const turnPolled = await workbenchAPI.turn(traceId, inactivityTimeoutMs, activityRef);
     if (signal.aborted) return;
 
     if (turnPolled.ok && turnPolled.data) {
diff --git a/web/hwlab-cloud-web/src/stores/workbench.ts b/web/hwlab-cloud-web/src/stores/workbench.ts
index b0c391e7..4bbb55ec 100644
--- a/web/hwlab-cloud-web/src/stores/workbench.ts
+++ b/web/hwlab-cloud-web/src/stores/workbench.ts
@@ -248,7 +248,7 @@ export const useWorkbenchStore = defineStore("workbench", () => {
   async function refreshTurnStatusByTraceId(traceId: string | null | undefined): Promise<void> {
     const id = firstNonEmptyString(traceId);
     if (!id) return;
-    const response = await api.agent.getAgentTurn(id, 8000, () => activityRef.value);
+    const response = await api.workbench.turn(id, 8000, () => activityRef.value);
     if (response.ok && response.data) {
       applyTurnStatusSnapshot(id, response.data);
       if (response.data.terminal === true || isTerminalMessageStatus(response.data.status)) completeTrace(id, response.data);
@@ -414,7 +414,7 @@ export const useWorkbenchStore = defineStore("workbench", () => {
   async function fetchTraceHydrationPage(traceId: string, sinceSeq: number): Promise<ApiResult<AgentChatResultResponse>> {
     let lastResult: ApiResult<AgentChatResultResponse> | null = null;
     for (let attempt = 0; attempt < TRACE_HYDRATION_MAX_ATTEMPTS; attempt += 1) {
-      const result = await api.agent.getAgentTrace(traceId, codeAgentTimeoutMs.value, () => activityRef.value, { sinceSeq, limit: TRACE_HYDRATION_PAGE_LIMIT });
+      const result = await api.workbench.traceEvents(traceId, codeAgentTimeoutMs.value, () => activityRef.value, { sinceSeq, limit: TRACE_HYDRATION_PAGE_LIMIT });
       if (result.ok && result.data) return result;
       lastResult = result;
       if (attempt < TRACE_HYDRATION_MAX_ATTEMPTS - 1) await delayTraceHydrationRetry(TRACE_HYDRATION_RETRY_DELAY_MS * (attempt + 1));
@@ -540,7 +540,7 @@ export const useWorkbenchStore = defineStore("workbench", () => {
   }
 
   async function validateAndReattachTrace(traceId: string): Promise<void> {
-    const result = await api.agent.getAgentTurn(traceId, 8000, () => activityRef.value);
+    const result = await api.workbench.turn(traceId, 8000, () => activityRef.value);
     if (!result.ok || !result.data) {
       await clearActiveTrace(traceId, result.status === 404 ? "reattach-result-not-found" : "reattach-result-unavailable");
       return;
@@ -629,7 +629,7 @@ export const useWorkbenchStore = defineStore("workbench", () => {
     if (terminalRealtimeRefreshInFlight.has(traceId)) return;
     terminalRealtimeRefreshInFlight.add(traceId);
     try {
-      const result = await api.agent.getAgentTurn(traceId, 8000, () => activityRef.value);
+      const result = await api.workbench.turn(traceId, 8000, () => activityRef.value);
       if (!result.ok || !result.data) return;
       applyTurnStatusSnapshot(traceId, result.data);
       if (result.data.terminal === true || isTerminalMessageStatus(result.data.status)) completeTrace(traceId, result.data);
@@ -760,7 +760,7 @@ export const useWorkbenchStore = defineStore("workbench", () => {
     await Promise.all(targets.map(async (message) => {
       const traceId = firstNonEmptyString(message.traceId, message.runnerTrace?.traceId);
       if (!traceId) return;
-      const result = await api.agent.getAgentTurn(traceId, 8000, () => activityRef.value);
+      const result = await api.workbench.turn(traceId, 8000, () => activityRef.value);
       if (!result.ok || !result.data) return;
       applyTurnStatusSnapshot(traceId, result.data);
     }));