fix: address code review findings

internal/database/database.go

@@ -15,7 +15,11 @@ type DB struct {
 
 // New opens a SQLite database at dbPath and runs schema migrations.
 func New(dbPath string) (*DB, error) {
-	conn, err := sql.Open("sqlite3", dbPath)
+	// The _foreign_keys=on DSN parameter enables foreign key enforcement on
+	// EVERY connection in the pool. A one-off "PRAGMA foreign_keys=ON" executed
+	// on the pooled *sql.DB only applies to the first connection and is lost on
+	// connections opened later by the pool, silently disabling the safety net.
+	conn, err := sql.Open("sqlite3", dbPath+"?_foreign_keys=on")
 	if err != nil {
 		return nil, fmt.Errorf("open database: %w", err)
 	}
@@ -26,12 +30,6 @@ func New(dbPath string) (*DB, error) {
 		return nil, fmt.Errorf("set WAL mode: %w", err)
 	}
 
-	// Enable foreign key enforcement.
-	if _, err := conn.Exec("PRAGMA foreign_keys=ON"); err != nil {
-		conn.Close()
-		return nil, fmt.Errorf("enable foreign keys: %w", err)
-	}
-
 	// Set busy timeout to handle concurrent write contention.
 	if _, err := conn.Exec("PRAGMA busy_timeout=5000"); err != nil {
 		conn.Close()

internal/database/external_releases.go

@@ -119,28 +119,6 @@ func SetReleaseIgnored(db *DB, rgid string, ignored bool) error {
 	return nil
 }
 
-// DeleteExternalReleasesByArtist removes all external_release rows for a given artist_id.
-func DeleteExternalReleasesByArtist(db *DB, artistID string) error {
-	_, err := db.Conn().Exec(
-		"DELETE FROM external_releases WHERE artist_id = ?",
-		artistID,
-	)
-	if err != nil {
-		return fmt.Errorf("delete external releases by artist: %w", err)
-	}
-	return nil
-}
-
-// CountExternalReleases returns the total number of external_release rows.
-func CountExternalReleases(db *DB) (int, error) {
-	var count int
-	err := db.Conn().QueryRow("SELECT COUNT(*) FROM external_releases").Scan(&count)
-	if err != nil {
-		return 0, fmt.Errorf("count external releases: %w", err)
-	}
-	return count, nil
-}
-
 // GetExternalReleasesByArtistWithCache returns cached external_release rows for a given artist_id
 // that are within the specified TTL.
 func GetExternalReleasesByArtistWithCache(db *DB, artistID string, ttl time.Duration) ([]ExternalRelease, error) {