Initial commit: CarrotAssistant backend (Go + Gin + SQLite, OpenAI-compatible agent runtime)

internal/store/db.go

@@ -0,0 +1,45 @@
+package store
+
+import (
+	"fmt"
+
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+)
+
+// Open opens (or creates) the SQLite database at path and runs GORM
+// AutoMigrate for all models. SQLite with WAL is used for single-instance
+// durability; the abstraction lives entirely in this package so a future
+// migration to Postgres stays localised.
+func Open(path string) (*gorm.DB, error) {
+	// _busy_timeout helps under concurrent writes; _foreign_keys enforces FK
+	// constraints that GORM expects; _journal_mode=WAL improves read/write
+	// concurrency for the single-file database.
+	dsn := fmt.Sprintf("%s?_busy_timeout=5000&_foreign_keys=on&_journal_mode=WAL", path)
+	db, err := gorm.Open(sqlite.Open(dsn), &gorm.Config{
+		// Silent: our handlers emit their own HTTP errors and frequently run
+		// "first-or-create" / 404 lookups whose ErrRecordNotFound would
+		// otherwise spam the operator's logs.
+		Logger: logger.Default.LogMode(logger.Silent),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("open sqlite: %w", err)
+	}
+
+	if err := db.AutoMigrate(
+		&AdminUser{},
+		&App{},
+		&ModelConfig{},
+		&Skill{},
+		&Session{},
+		&Message{},
+		&AuditLog{},
+	); err != nil {
+		return nil, fmt.Errorf("auto-migrate: %w", err)
+	}
+
+	// Compound uniqueness: a skill slug is unique per app. Enforced in code
+	// to avoid depending on DB-specific index syntax during migration.
+	return db, nil
+}