fix: move summary wait + session-complete into Stop hook to prevent lost summaries

SessionEnd has a 1.5s hardcoded cap from Claude Code (CLAUDE_CODE_SESSIONEND_HOOKS_TIMEOUT_MS),
making it unsuitable for waiting on async work. Previously, the Stop hook would fire-and-forget
the summarize request, then SessionEnd would immediately call deleteSession — aborting the SDK
agent mid-summary.

Now the Stop hook (120s timeout, no cap) owns the full lifecycle:
1. Queue summarize request
2. Poll new GET /api/sessions/status endpoint until queue drains
3. Call /api/sessions/complete after summary finishes

SessionEnd is now a true fire-and-forget fallback (process.exit(0) immediately).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

plugin/hooks/hooks.json

@@ -74,8 +74,8 @@
         "hooks": [
           {
             "type": "command",
-            "command": "node -e \"let d='';process.stdin.on('data',c=>d+=c);process.stdin.on('end',()=>{try{const{sessionId:s}=JSON.parse(d);if(!s){process.exit(0)}const r=require('http').request({hostname:'127.0.0.1',port:37777,path:'/api/sessions/complete',method:'POST',headers:{'Content-Type':'application/json'}},()=>process.exit(0));r.on('error',()=>process.exit(0));r.end(JSON.stringify({contentSessionId:s}));setTimeout(()=>process.exit(0),3000)}catch{process.exit(0)}})\"",
-            "timeout": 5
+            "command": "node -e \"let d='';process.stdin.on('data',c=>d+=c);process.stdin.on('end',()=>{try{const{sessionId:s}=JSON.parse(d);if(!s){process.exit(0)}const r=require('http').request({hostname:'127.0.0.1',port:37777,path:'/api/sessions/complete',method:'POST',headers:{'Content-Type':'application/json'}});r.on('error',()=>{});r.end(JSON.stringify({contentSessionId:s}));process.exit(0)}catch{process.exit(0)}})\"",
+            "timeout": 2
           }
         ]
       }