feat: add automation, reminders, notifications, msg search, session export, image analysis, host exec, PWA, Docker, E2E, CI/CD

- Automation: rules CRUD (in-memory store + API)
- Reminders: CRUD (in-memory store + API)
- Notifications: push interface for future push server
- Message search: API endpoint with DB-backed query
- Session export: /sessions/:id/export → Markdown
- Image analysis: API stub for multimodal LLM
- Host exec: API stub for Docker sandbox
- PWA: manifest.json + service worker
- Docker: Dockerfile + docker-compose.yml
- E2E: Playwright test scaffold
- CI/CD: GitHub Actions workflow (go test + tsc)

frontend/web/index.html

@@ -4,6 +4,7 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <link rel="icon" type="image/png" href="/images/cyrene-avatar.png" />
+    <link rel="manifest" href="/manifest.json" />
     <title>Cyrene — 昔涟</title>
   </head>
   <body class="bg-gray-950 text-gray-100">