Fix schema-output flag to only output data to stdout (#112)

* Initial plan

* Fix schema-output flag to only output data to stdout

Co-authored-by: danielsiegl <41949368+danielsiegl@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: danielsiegl <41949368+danielsiegl@users.noreply.github.com>

Author: Copilot

internal/filters/clean.go

@@ -68,7 +68,9 @@ func Clean(ctx context.Context, eng *sqlite.Engine, in io.Reader, out io.Writer,
 
 	// Use the new selective dumping method that excludes sqlite_sequence natively
 	// This now uses the logical filtering function from the filters package
-	if err := DumpTables(dumpCtx, eng, tmp.Name(), out, floatPrecision, dataOnly); err != nil {
+	// When schema is saved to a separate file, only output data to stdout
+	outputDataOnly := dataOnly || (schemaOutput != "")
+	if err := DumpTables(dumpCtx, eng, tmp.Name(), out, floatPrecision, outputDataOnly); err != nil {
 		slog.Error("SQLite selective dump failed", "error", err)
 		return err
 	}

internal/filters/diff.go

@@ -35,7 +35,9 @@ func Diff(ctx context.Context, eng *sqlite.Engine, dbFile string, out io.Writer,
 	}
 
 	// For data output, use DumpTables with filtering
-	if err := DumpTables(ctx, eng, dbFile, out, 9, dataOnly); err != nil {
+	// When schema is saved to a separate file, only output data to stdout
+	outputDataOnly := dataOnly || (schemaOutput != "")
+	if err := DumpTables(ctx, eng, dbFile, out, 9, outputDataOnly); err != nil {
 		slog.Error("Diff dump failed", "error", err)
 		return err
 	}