feat: multi-customer architecture + Z-Park support + Gitea migration scripts

Multi-customer config system:
- CUSTOMER env var selects customer (tianpu/zpark)
- customers/tianpu/config.yaml — Tianpu branding, collectors, features
- customers/zpark/config.yaml — Z-Park branding, Sungrow collector
- GET /api/v1/branding endpoint for customer-specific branding
- main.py loads customer config for app title, CORS, logging
- Collector manager filters by customer's enabled collectors

Z-Park (中关村医疗器械园) support:
- Sungrow iSolarCloud API collector (sungrow_collector.py)
- Z-Park device definitions (10 inverters, 8 combiner boxes, 22+ buildings)
- Z-Park TOU pricing config (Beijing 2026 rates)
- Z-Park seed script (seed_zpark.py)

Gitea migration scripts (Mac Studio → labmac3):
- 5 migration scripts + README in scripts/gitea-migration/
- Creates 3-repo structure: ems-core, tp-ems, zpark-ems

Version: v1.0.0

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

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "frontend",
   "private": true,
-  "version": "0.0.0",
+  "version": "1.0.0",
   "type": "module",
   "scripts": {
     "dev": "vite",