feat(store): add PostgreSQL foundation [T-009]

Sense/internal/config/config.go

@@ -13,6 +13,7 @@ import (
 
 const (
 	defaultHTTPAddress     = "127.0.0.1:8080"
+	defaultDatabaseDriver  = "sqlite"
 	defaultDatabaseDSN     = "file:data/sense.db"
 	defaultMediaMTXURL     = "http://127.0.0.1:9997"
 	defaultReconcilePeriod = 5 * time.Second
@@ -23,6 +24,7 @@ const (
 type Config struct {
 	HTTPAddress       string
 	AllowNonLoopback  bool
+	DatabaseDriver    string
 	DatabaseDSN       string
 	MediaMTXURL       string
 	ReconcileInterval time.Duration
@@ -58,6 +60,7 @@ func Load() (Config, error) {
 	cfg := Config{
 		HTTPAddress:       stringEnv("SENSE_HTTP_ADDR", defaultHTTPAddress),
 		AllowNonLoopback:  allow,
+		DatabaseDriver:    stringEnv("SENSE_DB_DRIVER", defaultDatabaseDriver),
 		DatabaseDSN:       stringEnv("SENSE_DB_DSN", defaultDatabaseDSN),
 		MediaMTXURL:       stringEnv("SENSE_MEDIAMTX_URL", defaultMediaMTXURL),
 		ReconcileInterval: reconcilePeriod,
@@ -86,6 +89,16 @@ func (c Config) Validate() error {
 	if c.DatabaseDSN == "" {
 		return fmt.Errorf("SENSE_DB_DSN must not be empty")
 	}
+	databaseDriver := strings.ToLower(strings.TrimSpace(c.DatabaseDriver))
+	if databaseDriver == "" {
+		databaseDriver = defaultDatabaseDriver
+	}
+	if databaseDriver != "sqlite" && databaseDriver != "postgres" {
+		return fmt.Errorf("SENSE_DB_DRIVER must be sqlite or postgres")
+	}
+	if databaseDriver == "postgres" && strings.HasPrefix(c.DatabaseDSN, "file:") {
+		return fmt.Errorf("postgres SENSE_DB_DRIVER requires an explicit PostgreSQL SENSE_DB_DSN")
+	}
 	mediaURL, err := url.Parse(c.MediaMTXURL)
 	if err != nil || mediaURL.Scheme == "" || mediaURL.Host == "" {
 		return fmt.Errorf("invalid SENSE_MEDIAMTX_URL")