fix: preserve code agent sessions after turn failures

internal/cloud/code-agent-chat.ts

@@ -1324,9 +1324,9 @@ function errorTaxonomy(code, error = {}) {
     },
     session_failed: {
       layer: "session",
-      category: "session_blocked",
+      category: "runner_blocked",
       retryable: true,
-      userMessage: "Code Agent session 已失败，可重新发送建立新的 session。"
+      userMessage: "Code Agent 当前 turn 已失败，session/thread 已保留，可继续发送下一条消息。"
     },
     session_interrupted: {
       layer: "session",
@@ -1344,13 +1344,13 @@ function errorTaxonomy(code, error = {}) {
       layer: "session",
       category: "timeout",
       retryable: true,
-      userMessage: "Code Agent session 已超时，输入和 trace 已保留，可重试上一条消息。"
+      userMessage: "Code Agent 当前 turn 已超时，输入、trace、session/thread 已保留，可继续发送下一条消息。"
     },
     session_error: {
       layer: "session",
-      category: "session_blocked",
+      category: "runner_blocked",
       retryable: true,
-      userMessage: "Code Agent session 返回错误，输入和 trace 已保留，可重试上一条消息。"
+      userMessage: "Code Agent 当前 turn 返回错误，输入、trace、session/thread 已保留，可继续发送下一条消息。"
     },
     runner_unavailable: {
       layer: "runner",