feat(infrastructure): Add night-scheduler for automated Docker service shutdown

Implement dashboard-controlled night mode for automatic Docker service
management. Services are stopped at a configurable time (default 22:00)
and restarted in the morning (default 06:00).

Features:
- Python/FastAPI scheduler service (port 8096)
- Admin dashboard API routes at /api/admin/night-mode
- Toggle for enable/disable night mode
- Time picker for shutdown and startup times
- Manual start/stop buttons for immediate actions
- Excluded services (night-scheduler, nginx always run)

Files added:
- night-scheduler/scheduler.py - Main scheduler with REST API
- night-scheduler/Dockerfile - Container with Docker CLI
- night-scheduler/requirements.txt - FastAPI, Uvicorn, Pydantic
- night-scheduler/tests/test_scheduler.py - Unit tests
- admin-v2/app/api/admin/night-mode/* - API proxy routes
- .claude/rules/night-scheduler.md - Developer documentation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

night-scheduler/requirements.txt

@@ -0,0 +1,8 @@
+fastapi==0.109.0
+uvicorn[standard]==0.27.0
+pydantic==2.5.3
+
+# Testing
+pytest==8.0.0
+pytest-asyncio==0.23.0
+httpx==0.26.0