fix: address 5 edge cases from review-work findings

- C3: include command args in auto-slash-command dedup key
- H2: track completed task summaries for ALL COMPLETE message
- H9: increment tmux close retry count on re-mark
- H8: detect stale MCP connections after disconnect+reconnect race
- H8: guard disconnectedSessions growth for non-MCP sessions
- C1: await tmux cleanup in plugin dispose lifecycle

src/plugin-dispose.ts

@@ -7,9 +7,12 @@ export function createPluginDispose(args: {
   skillMcpManager: {
     disconnectAll: () => Promise<void>
   }
+  tmuxSessionManager: {
+    cleanup: () => Promise<void>
+  }
   disposeHooks: () => void
 }): PluginDispose {
-  const { backgroundManager, skillMcpManager, disposeHooks } = args
+  const { backgroundManager, skillMcpManager, tmuxSessionManager, disposeHooks } = args
   let disposePromise: Promise<void> | null = null
 
   return async (): Promise<void> => {
@@ -20,7 +23,10 @@ export function createPluginDispose(args: {
 
     disposePromise = (async (): Promise<void> => {
       backgroundManager.shutdown()
-      await skillMcpManager.disconnectAll()
+      await Promise.all([
+        skillMcpManager.disconnectAll(),
+        tmuxSessionManager.cleanup(),
+      ])
       disposeHooks()
     })()