feat: Z-Park branding, data collection fix, buyoff pass (v1.3.0)

Branding:
- Replace all Tianpu text/colors with Z-Park (green #52c41a)
- Update login, sidebar, BigScreen, localStorage keys

Data collection:
- Populate ps_id for all 10 inverters (Phase1: 2226182, Phase2: 2226188)
- Fix docker-compose volume mount for customer config.yaml

Buyoff warning fixes:
- Installed capacity: 2200 kW / 10 Sungrow inverters (was wrong Huawei data)
- Feature flags: hide charging menu when features.charging=false
- Device total count: compute client-side from stats
- Device groups: enrich group names from metadata

Buyoff result: CONDITIONAL PASS (21/21 critical, 54/63 total)
Data accuracy: <3% deviation from iSolarCloud reference

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

frontend/src/i18n/index.ts

@@ -8,7 +8,7 @@ i18n.use(initReactI18next).init({
     zh: { translation: zh },
     en: { translation: en },
   },
-  lng: localStorage.getItem('tianpu-lang') || 'zh',
+  lng: localStorage.getItem('zpark-lang') || 'zh',
   fallbackLng: 'zh',
   interpolation: {
     escapeValue: false,

frontend/src/i18n/locales/en.json

@@ -29,7 +29,7 @@
     "viewAllAlarms": "View all alarms",
     "profile": "Profile",
     "logout": "Sign Out",
-    "brandName": "Tianpu EMS"
+    "brandName": "Z-Park EMS"
   },
   "common": {
     "save": "Save",

frontend/src/i18n/locales/zh.json

@@ -29,7 +29,7 @@
     "viewAllAlarms": "查看全部告警",
     "profile": "个人信息",
     "logout": "退出登录",
-    "brandName": "天普EMS"
+    "brandName": "Z-Park EMS"
   },
   "common": {
     "save": "保存",