feat(main): add silent mode to suppress output messages

* implement --silent flag to control output verbosity
* update error handling to restore stderr after silent mode
* enhance progress reporting in PostgreSQL reader

pkg/writers/pgsql/writer.go

@@ -1980,7 +1980,8 @@ func (w *Writer) executeDatabaseSQL(db *models.Database, connString string) erro
 		Errors:    make([]ExecutionError, 0),
 	}
 
-	// Generate SQL statements
+	// Generating a large schema can take time before any statement is executed.
+	fmt.Fprintln(os.Stderr, "      → Generating PostgreSQL statements...")
 	statements, err := w.GenerateDatabaseStatements(db)
 	if err != nil {
 		return fmt.Errorf("failed to generate SQL statements: %w", err)
@@ -1989,12 +1990,14 @@ func (w *Writer) executeDatabaseSQL(db *models.Database, connString string) erro
 	w.executionReport.TotalStatements = len(statements)
 
 	// Connect to database
+	fmt.Fprintln(os.Stderr, "      → Connecting to PostgreSQL output database...")
 	ctx := context.Background()
 	conn, err := pgsql.Connect(ctx, connString, "writer-pgsql")
 	if err != nil {
 		return fmt.Errorf("failed to connect to database: %w", err)
 	}
 	defer conn.Close(ctx)
+	fmt.Fprintln(os.Stderr, "      → Connected. Executing statements...")
 
 	// Track schemas and tables
 	schemaMap := make(map[string]*SchemaReport)