Topdata Migration (#2)

Native topdata migration summary

- Replaced the legacy 2dabuilder runtime path with the native topdata builder.
- Native build, validate, compare, and convert flows now cover the canonical topdata pipeline.
- compare-topdata is now a native self-check; legacy reference-builder runtime usage was removed.
- Parts generation follows the native asset-scan contract and uses sow-assets via project asset resolution.
- Generated feat families, class-feat injects, masterfeat/successor expansion, and dataset-derived feat generation were brought to parity and regression-covered.
- Remaining mirrored datasets were migrated into native-owned canonical data while preserving lock IDs.
- normalize-topdata bridge behavior and migration-era ownership markers were removed.
- Documentation was rewritten around the native workflow and active contracts were cleaned up.
- Final hardening pass removed stale validator assumptions and cleaned ignored/generated artifacts for PR readiness.

Reviewed-on: https://gitea.westgate.pw/ShadowsOverWestgate/sow-tools/pulls/2
Co-authored-by: vickydotbat <vickydotbat@tutamail.com>
Co-committed-by: vickydotbat <vickydotbat@tutamail.com>

internal/topdata/base_dialog_migrate.go

@@ -0,0 +1,41 @@
+package topdata
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+)
+
+func importLegacyBaseDialog(referenceBuilderDir, sourceDir string) (int, error) {
+	legacyPath := filepath.Join(referenceBuilderDir, "tlk", "base.json")
+	if _, err := os.Stat(legacyPath); err != nil {
+		if os.IsNotExist(err) {
+			return 0, nil
+		}
+		return 0, err
+	}
+
+	targetPath := filepath.Join(sourceDir, "base_dialog.json")
+	if fileExists(targetPath) {
+		current, err := loadJSONObject(targetPath)
+		if err == nil {
+			if entries, ok := current["entries"].(map[string]any); ok && len(entries) > 0 {
+				return 0, nil
+			}
+		}
+	}
+
+	obj, err := loadJSONObject(legacyPath)
+	if err != nil {
+		return 0, err
+	}
+	raw, err := json.MarshalIndent(obj, "", "  ")
+	if err != nil {
+		return 0, err
+	}
+	raw = append(raw, '\n')
+	if err := os.WriteFile(targetPath, raw, 0o644); err != nil {
+		return 0, err
+	}
+	return 1, nil
+}