feat: add customer-owned frontend, device config, pricing (v1.2.0)

- Add frontend/ at root (customer's own React app, all pages)
- Add customers/tianpu/devices.json (17 devices, 375kW PV)
- Add customers/tianpu/pricing.json (Beijing TOU 4-tier)
- Add customers/tianpu/hooks/__init__.py
- Add .githooks/pre-commit to block core/ modifications
- Add CLAUDE.md, .gitignore
- Update docker-compose.override.yml frontend -> ./frontend
- Pin bcrypt==4.0.1 in requirements.txt

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

.gitignore

@@ -0,0 +1,9 @@
+.env
+*.log
+__pycache__/
+*.pyc
+.DS_Store
+node_modules/
+dist/
+venv/
+docker-compose.ports.yml