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.)

internal/db/db.go

@@ -0,0 +1,51 @@
+package db
+
+import (
+	"log/slog"
+	"strings"
+	"time"
+
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+
+	"github.com/llamalink/llamalink/internal/config"
+)
+
+func Open(cfg *config.Config) (*gorm.DB, error) {
+	dsn := strings.TrimPrefix(cfg.DatabaseURL, "sqlite://")
+	if dsn == cfg.DatabaseURL {
+		dsn = cfg.DatabaseURL
+	}
+
+	gormConfig := &gorm.Config{
+		Logger: logger.Default.LogMode(logger.Silent),
+	}
+
+	db, err := gorm.Open(sqlite.Open(dsn), gormConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	sqlDB, err := db.DB()
+	if err != nil {
+		return nil, err
+	}
+
+	sqlDB.SetMaxOpenConns(cfg.DatabaseMaxOpenConns)
+	sqlDB.SetMaxIdleConns(cfg.DatabaseMaxIdleConns)
+	sqlDB.SetConnMaxLifetime(time.Duration(cfg.DatabaseConnMaxLifetime) * time.Second)
+
+	return db, nil
+}
+
+func Migrate(db *gorm.DB) error {
+	slog.Info("running database migrations")
+	return db.AutoMigrate(
+		&ApiKey{},
+		&Model{},
+		&UsageLog{},
+		&Quota{},
+		&Webhook{},
+	)
+}