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/features/skill-mcp-manager/cleanup.ts

@@ -87,7 +87,16 @@ async function cleanupIdleClients(state: SkillMcpManagerState): Promise<void> {
 }
 
 export async function disconnectSession(state: SkillMcpManagerState, sessionID: string): Promise<void> {
-  state.disconnectedSessions.add(sessionID)
+  let hasPendingForSession = false
+  for (const key of state.pendingConnections.keys()) {
+    if (key.startsWith(`${sessionID}:`)) {
+      hasPendingForSession = true
+      break
+    }
+  }
+  if (hasPendingForSession) {
+    state.disconnectedSessions.add(sessionID)
+  }
   const keysToRemove: string[] = []
 
   for (const [key, managed] of state.clients.entries()) {