fix cycling

Author: charlesvien

PROBLEM.md

@@ -0,0 +1,82 @@
+# Agent Process Lifecycle Bug
+
+## Problem Summary
+
+Multiple interrelated bugs causing:
+1. **Duplicate agents** - Multiple agent processes run for same task, causing interleaved responses
+2. **App hangs on shutdown** - Cleanup waits indefinitely for unresponsive agent processes
+3. **Orphaned processes** - Agent subprocesses not properly terminated
+
+## Root Causes
+
+### Race Condition #1: Renderer (sessionStore.ts:955-1012)
+```typescript
+if (connectAttempts.has(taskId)) return;  // Line 956 - check
+// ... async work ...
+connectAttempts.add(taskId);               // Line 1012 - add (too late!)
+```
+Two rapid calls both pass the check before either adds to the set.
+
+### Race Condition #2: Main Process (service.ts:388-497)
+```typescript
+const existing = this.sessions.get(taskRunId);  // Line 389 - check
+if (existing) return existing;
+// ... 100+ lines of async work ...
+this.sessions.set(taskRunId, session);          // Line 497 - set (too late!)
+```
+Also: Sessions keyed by `taskRunId`, not `taskId` - two runs for same task both create agents.
+
+### No Cleanup Timeout (app-lifecycle/service.ts:22-40)
+```typescript
+await container.unbindAll();  // Line 26 - can hang forever
+```
+If agent subprocess doesn't respond, cleanup never completes, app never quits.
+
+---
+
+## Key Files
+
+| File | Role |
+|------|------|
+| `apps/twig/src/main/services/agent/service.ts` | Main process agent management - sessions Map, getOrCreateSession, cleanupSession |
+| `apps/twig/src/renderer/features/sessions/stores/sessionStore.ts` | Renderer session management - connectAttempts Set, connectToTask |
+| `apps/twig/src/main/services/app-lifecycle/service.ts` | App shutdown - calls container.unbindAll() |
+| `packages/agent/src/agent.ts` | Agent wrapper - cleanup() method |
+| `packages/agent/src/adapters/acp-connection.ts` | ACP connection - actual cleanup logic |
+
+---
+
+## Fix Plan
+
+### Phase 1: Main Process Mutex + Kill-Before-Create
+- Add `sessionsByTaskId` Map to track by taskId (not just taskRunId)
+- Add `pendingCreations` Map to prevent race conditions
+- Before creating new session, clean up any existing session for same taskId
+
+### Phase 2: Cleanup Timeout
+- Race `agent.cleanup()` against 5-second timeout
+- Call `forceCleanup()` if timeout
+
+### Phase 3: Force Cleanup Method
+- Add `forceCleanup()` to Agent class that aborts the session controller
+
+### Phase 4: App Shutdown Timeout
+- Add 10-second overall timeout to `shutdown()`
+
+### Phase 5: Renderer Mutex
+- Replace `connectAttempts` Set with Promise-based locking
+- Check "connecting" status, not just "connected"
+
+---
+
+## Debug Log Location
+
+When the app hangs on shutdown, check:
+```
+~/Library/Logs/twig/main.log
+```
+
+Or tail it live:
+```bash
+tail -f ~/Library/Logs/twig/main.log | grep -E "(AGENT_DEBUG|cleanupSession|getOrCreateSession|shutdown)"
+```

apps/twig/src/renderer/features/sessions/stores/sessionStore.ts

@@ -47,7 +47,7 @@ export type ExecutionMode =
 export function getExecutionModes(
   allowBypassPermissions: boolean,
 ): ExecutionMode[] {
-  const modes: ExecutionMode[] = ["plan", "default", "acceptEdits"];
+  const modes: ExecutionMode[] = ["default", "acceptEdits", "plan"];
   if (allowBypassPermissions) {
     modes.push("bypassPermissions");
   }