Initial commit: LlamaLink Go rewrite

Complete rewrite from Python/FastAPI to Go/Gin:
- Go backend: auth (API keys + bcrypt), llama.cpp subprocess manager,
  hot-swap multi-model, rate limiting, quota system, webhooks
- Vue 3 SPA admin panel (src/) with Tailwind CSS
- Deployment: Docker multi-stage, docker-compose, nginx, systemd
- GORM/SQLite models: ApiKey, Model, UsageLog, Quota, Webhook
- REST API: /api/v1/admin/* (keys, models, chat, usage, health)
- Embedded frontend via go:embed (build output at web/dist/)

Removed legacy Python artifacts (app/, tests/, pyproject.toml, etc.)

.env.example

@@ -0,0 +1,28 @@
+LLAMALINK_ENV=development
+LLAMALINK_HOST=0.0.0.0
+LLAMALINK_PORT=8000
+LLAMALINK_SECRET_KEY=change-me-in-production
+
+DATABASE_URL=sqlite:///./llamalink.db
+DATABASE_MAX_OPENConns=25
+DATABASE_MAX_IDLE_CONNS=5
+DATABASE_CONN_MAX_LIFETIME=300
+
+MANAGE_LLAMA_SERVER=true
+LLAMA_SERVER_BIN=/usr/local/bin/llama-server
+LLAMA_SERVER_HOST=127.0.0.1
+LLAMA_SERVER_PORT=8080
+LLAMA_SERVER_STARTUP_TIMEOUT=120
+LLAMA_SERVER_STOP_TIMEOUT=10
+MODEL_SWAP_COOLDOWN=2
+
+RATE_LIMIT_PER_MINUTE=60
+RATE_LIMIT_STORAGE=memory
+# RATE_LIMIT_REDIS_URL=redis://localhost:6379/0
+
+ADMIN_TOKEN=change-me-in-production
+
+LOG_LEVEL=info
+LOG_FORMAT=json
+
+# WEBHOOK_SECRET=your-webhook-secret-here