fix: address review-work round 3 findings (async shutdown, signal generation, stale test name)

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

@@ -19,6 +19,7 @@ export function registerProcessCleanup(state: SkillMcpManagerState): void {
   state.cleanupRegistered = true
 
   const cleanup = async (): Promise<void> => {
+    state.shutdownGeneration++
     for (const managed of state.clients.values()) {
       await closeManagedClient(managed)
     }

src/features/skill-mcp-manager/connection-race.test.ts

@@ -142,7 +142,7 @@ describe("getOrCreateClient disconnect race", () => {
     expect(createdTransports[0]?.close).toHaveBeenCalledTimes(1)
   })
 
-  it("#given session A in disconnectedSessions #when new connection is requested for session A #then session A is removed from disconnectedSessions and connection proceeds normally", async () => {
+  it("#given session A in disconnectedSessions #when new connection is requested for session A #then connection proceeds normally and disconnectedSessions entry is retained for pending race protection", async () => {
     const state = createState()
     const info = createClientInfo("session-a")
     const clientKey = createClientKey(info)