fix fragile hak packing

internal/topdata/top_package.go

@@ -211,11 +211,12 @@ func collectTopPackageResources(p *project.Project, compiled2DADir string) ([]er
 			if d.IsDir() {
 				return nil
 			}
-			if strings.HasPrefix(filepath.Base(path), ".") {
+			rel, err := filepath.Rel(assetsDir, path)
-				return nil
+			if err != nil {
+				return err
 			}
-			if strings.EqualFold(filepath.Ext(path), ".md") {
+			if skipTopPackageAsset(rel) {
-				return nil // docs (AGENTS.md, README.md, ...) are never HAK resources
+				return nil
 			}
 			resource, err := topPackageResourceFromPath(path)
 			if err != nil {
@@ -388,6 +389,25 @@ func newestMatchingAutogenOverrideInput(scanRoot string, include []string) (time
 	return newest, newestPath, nil
 }
 
+// skipTopPackageAsset reports whether a file under assets/ is not a HAK
+// resource and must be ignored by both validation and packing: anything in a
+// hidden or underscore-prefixed directory (working dirs like _candidates),
+// hidden files, docs, and any extension that is not a known NWN ResType
+// (erf.extensionTypes is the whitelist). rel is the path relative to assets/.
+func skipTopPackageAsset(rel string) bool {
+	for _, part := range strings.Split(filepath.ToSlash(rel), "/") {
+		if strings.HasPrefix(part, ".") || strings.HasPrefix(part, "_") {
+			return true
+		}
+	}
+	if strings.EqualFold(filepath.Ext(rel), ".md") {
+		return true
+	}
+	ext := strings.TrimPrefix(strings.ToLower(filepath.Ext(rel)), ".")
+	_, ok := erf.HAKResourceTypeForExtension(ext)
+	return !ok
+}
+
 func topPackageResourceFromPath(path string) (erf.Resource, error) {
 	extension := strings.TrimPrefix(strings.ToLower(filepath.Ext(path)), ".")
 	resourceType, ok := erf.HAKResourceTypeForExtension(extension)

internal/topdata/topdata.go

@@ -12,7 +12,6 @@ import (
 	"strconv"
 	"strings"
 
-	"git.westgate.pw/ShadowsOverWestgate/sow-tools/internal/erf"
 	"git.westgate.pw/ShadowsOverWestgate/sow-tools/internal/project"
 )
 
@@ -2230,22 +2229,11 @@ func validateTopPackageAssets(sourceDir, dataDir string, report *ValidationRepor
 		if err != nil {
 			return err
 		}
-		if strings.HasPrefix(filepath.Base(path), ".") {
+		if skipTopPackageAsset(rel) {
-			return nil
+			return nil // not a NWN ResType (script, doc, _work dir, ...): never packed, never checked
-		}
-		if strings.EqualFold(filepath.Ext(path), ".md") {
-			return nil // docs (AGENTS.md, README.md, ...) are never HAK resources
 		}
 		base := strings.ToLower(strings.TrimSuffix(filepath.Base(path), filepath.Ext(path)))
 		ext := strings.TrimPrefix(strings.ToLower(filepath.Ext(path)), ".")
-		if _, ok := erf.HAKResourceTypeForExtension(ext); !ok {
-			report.Diagnostics = append(report.Diagnostics, Diagnostic{
-				Severity: SeverityError,
-				Path:     path,
-				Message:  fmt.Sprintf("unsupported topdata asset HAK resource extension %q", filepath.Ext(path)),
-			})
-			return nil
-		}
 		key := base + "." + ext
 		if previous, ok := seen[key]; ok {
 			report.Diagnostics = append(report.Diagnostics, Diagnostic{

internal/topdata/topdata_test.go

@@ -15116,6 +15116,60 @@ func writeBytes(t *testing.T, path string, content []byte) {
 	}
 }
 
+func TestSkipTopPackageAsset(t *testing.T) {
+	skipped := []string{
+		"gui/regions/comfyui-generate.sh", // non-NWN extension
+		"gui/regions/_candidates/abyss.opt4.png",
+		"gui/.hidden/banner.png",
+		"gui/.DS_Store",
+		"gui/AGENTS.md",
+		"gui/noextension",
+	}
+	kept := []string{
+		"gui/regions/abyss.png",
+		"2da-src/placeables.2da",
+		"tex/floor01.dds",
+	}
+	for _, rel := range skipped {
+		if !skipTopPackageAsset(rel) {
+			t.Errorf("expected %s to be skipped", rel)
+		}
+	}
+	for _, rel := range kept {
+		if skipTopPackageAsset(rel) {
+			t.Errorf("expected %s to be kept", rel)
+		}
+	}
+}
+
+func TestValidateTopPackageAssetsIgnoresNonNWNFiles(t *testing.T) {
+	dir := t.TempDir()
+	assets := filepath.Join(dir, "assets", "gui", "regions")
+	candidates := filepath.Join(assets, "_candidates")
+	if err := os.MkdirAll(candidates, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	for path, content := range map[string]string{
+		filepath.Join(assets, "comfyui-generate.sh"):  "#!/bin/sh",
+		filepath.Join(assets, "abyss.png"):            "png",
+		filepath.Join(candidates, "abyss.opt4.png"):   "png",
+		filepath.Join(candidates, "notes.txt.backup"): "junk",
+	} {
+		if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	dataDir := filepath.Join(dir, "data")
+	if err := os.MkdirAll(dataDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	var report ValidationReport
+	validateTopPackageAssets(dir, dataDir, &report)
+	for _, d := range report.Diagnostics {
+		t.Errorf("unexpected diagnostic: %s: %s", d.Path, d.Message)
+	}
+}
+
 func TestValidateTopPackageAssetsSkipsMarkdown(t *testing.T) {
 	dir := t.TempDir()
 	assets := filepath.Join(dir, "assets", "gui")