feat: enterprise-level enhancement — 12 modules complete

New modules:
- Energy Quota Management (定额管理)
- Cost/Expense Analysis with TOU pricing (费用分析)
- Sub-item Energy Analysis (分项分析)
- EV Charging Station Management (充电桩管理) — 8 models, 6 pages
- Enhanced Energy Analysis — loss, YoY, MoM comparison
- Alarm Analytics — trends, MTTR, top devices, rule toggle
- Maintenance & Work Orders (运维管理) — inspections, repair orders, duty
- Data Query Module (数据查询)
- Equipment Topology (设备拓扑)
- Management System (管理体系) — regulations, standards, processes

Infrastructure:
- Redis caching layer with decorator
- Redis Streams data ingestion buffer
- Hourly/daily/monthly aggregation engine
- Rate limiting & request ID middleware
- 6 Alembic migrations (003-008), 21 new tables
- Extended seed data for all modules

Stats: 120+ API routes, 12 pages, 27 tabs, 37 database tables

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

.gitignore

@@ -1,6 +1,8 @@
 __pycache__/
 *.pyc
 .env.local
+.env
+backend/.env
 node_modules/
 dist/
 .next/
@@ -10,3 +12,4 @@ venv/
 *.log
 .DS_Store
 *.db
+backend/reports/