fix: migration runner idempotente e seeds com UNIQUE constraint

Runner agora checa schema_migrations antes de rodar cada SQL — sem
reexecução de seeds a cada startup. Quests: UNIQUE(title, quest_type).
Cosmetics: UNIQUE(name), tipos corrigidos para hair/shirt/pants/shoes.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

apps/api/internal/migration/migration.go

@@ -33,10 +33,26 @@ var m007 string
 var m008 string
 
 func Run(ctx context.Context, pool *pgxpool.Pool) error {
+	// Bootstrap: ensure schema_migrations table exists before checking versions.
+	if _, err := pool.Exec(ctx, `
+		CREATE TABLE IF NOT EXISTS schema_migrations (
+			version    INTEGER PRIMARY KEY,
+			applied_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW()
+		)
+	`); err != nil {
+		return fmt.Errorf("bootstrap schema_migrations: %w", err)
+	}
+
 	migrations := []string{m001, m002, m003, m004, m005, m006, m007, m008}
 	for i, sql := range migrations {
+		version := i + 1
+		var applied bool
+		_ = pool.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM schema_migrations WHERE version=$1)`, version).Scan(&applied)
+		if applied {
+			continue
+		}
 		if _, err := pool.Exec(ctx, sql); err != nil {
-			return fmt.Errorf("migration %03d: %w", i+1, err)
+			return fmt.Errorf("migration %03d: %w", version, err)
 		}
 	}
 	return nil