feat: customer frontend, Sungrow collector fixes, real data (v1.2.0)

- Add frontend/ at root (no Three.js, no Charging, green #52c41a theme)
- Fix Sungrow collector: add curPage/size params, unit conversion
- Fix station-level dedup to prevent double-counting
- Add shared token cache for API rate limit protection
- Add .githooks/pre-commit, CLAUDE.md, .gitignore
- Update docker-compose.override.yml frontend -> ./frontend
- Pin bcrypt in requirements.txt
- Add BUYOFF_RESULTS_2026-04-05.md (39/43 pass)
- Data accuracy: 0.0% diff vs iSolarCloud

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

CLAUDE.md

@@ -0,0 +1,23 @@
+# ZPARK-EMS (中关村医疗器械园) Development Guidelines
+
+## Overview
+Customer project for Z-Park Medical Device Hub. Uses ems-core via git subtree in `core/`.
+
+## CRITICAL: Do NOT modify core/ directly
+The `core/` directory is a git subtree from ems-core. All core changes must be made in the ems-core repository first.
+
+## Project Structure
+- `core/` — git subtree from ems-core (READ-ONLY in this repo)
+- `customers/zpark/` — Customer configuration (config.yaml, devices.json, pricing.json, hooks/)
+- `scripts/` — Seeding and admin tools
+- `docker-compose.override.yml` — Customer-specific Docker overrides
+
+## Deployment
+```bash
+cp .env.example .env
+docker compose -f core/docker-compose.yml -f docker-compose.override.yml up -d
+docker compose -f core/docker-compose.yml -f docker-compose.override.yml exec backend python scripts/seed_zpark.py
+```
+
+## Default Login
+- admin / admin123