fix: [AI-6771] cancel() race condition and idle state on normal loop exit

packages/opencode/src/session/processor.ts

@@ -533,6 +533,18 @@ export namespace SessionProcessor {
                 sessionID: input.assistantMessage.sessionID,
                 error: input.assistantMessage.error,
               })
+              // altimate_change start — telemetry for unhandled streaming errors (non-retry, non-overflow)
+              // Covers: MessageAbortedError (Stop/dispose), UnknownError (SSE chunk timeout),
+              // APIError (provider failures after retry exhaustion), AuthError, and any other streaming error.
+              Telemetry.track({
+                type: "error",
+                timestamp: Date.now(),
+                session_id: input.assistantMessage.sessionID,
+                error_name: error.name,
+                error_message: (error.data as any)?.message ?? String((e as any)?.message ?? ""),
+                context: "streaming",
+              })
+              // altimate_change end
               // altimate_change start — SessionStatus.set became async; await so idle state flushes before exit
               await SessionStatus.set(input.sessionID, { type: "idle" })
               // altimate_change end

packages/opencode/src/session/prompt.ts

@@ -303,13 +303,15 @@ export namespace SessionPrompt {
     const s = state()
     const match = s[sessionID]
     if (!match) {
+      // Session already ended or was never started — set idle directly since no processor will do it
       await SessionStatus.set(sessionID, { type: "idle" })
       return
     }
     match.abort.abort()
     delete s[sessionID]
-    await SessionStatus.set(sessionID, { type: "idle" })
-    return
+    // Do NOT set idle status here — on abort the processor's catch block
+    // publishes session.error THEN sets idle, preserving correct event ordering.
+    // On normal completion, loop() sets idle after the while loop exits (see below).
   }
   // altimate_change end
 
@@ -1110,6 +1112,11 @@ export namespace SessionPrompt {
       }
       continue
     }
+    // altimate_change start — set idle on normal loop exit; abort path is handled by processor catch block
+    if (!abort.aborted) {
+      await SessionStatus.set(sessionID, { type: "idle" })
+    }
+    // altimate_change end
     SessionCompaction.prune({ sessionID })
     // altimate_change start — session end telemetry
     const outcome = abort.aborted