s3tables: Fix remaining policy error handling in namespace and bucket handlers

Replace silent error swallowing (err == nil) with proper error distinction
for bucket policy reads. Now properly checks ErrAttributeNotFound and
propagates other errors as internal server errors.

Fixed 5 locations:
- handleCreateNamespace (policy fetch)
- handleDeleteNamespace (policy fetch)
- handleListNamespaces (policy fetch)
- handleGetNamespace (policy fetch)
- handleGetTableBucket (policy fetch)

This prevents masking of filer issues when policies cannot be read due
to I/O errors or other transient failures.

weed/s3api/s3tables/handler_bucket_get_list_delete.go

@@ -49,6 +49,8 @@ func (h *S3TablesHandler) handleGetTableBucket(w http.ResponseWriter, r *http.Re
 		policyData, err := h.getExtendedAttribute(r.Context(), client, bucketPath, ExtendedKeyPolicy)
 		if err == nil {
 			bucketPolicy = string(policyData)
+		} else if !errors.Is(err, ErrAttributeNotFound) {
+			return fmt.Errorf("failed to fetch bucket policy: %v", err)
 		}
 
 		return nil

weed/s3api/s3tables/handler_namespace.go

@@ -59,6 +59,8 @@ func (h *S3TablesHandler) handleCreateNamespace(w http.ResponseWriter, r *http.R
 		policyData, err := h.getExtendedAttribute(r.Context(), client, bucketPath, ExtendedKeyPolicy)
 		if err == nil {
 			bucketPolicy = string(policyData)
+		} else if !errors.Is(err, ErrAttributeNotFound) {
+			return fmt.Errorf("failed to fetch bucket policy: %v", err)
 		}
 
 		return nil
@@ -182,6 +184,8 @@ func (h *S3TablesHandler) handleGetNamespace(w http.ResponseWriter, r *http.Requ
 		policyData, err := h.getExtendedAttribute(r.Context(), client, bucketPath, ExtendedKeyPolicy)
 		if err == nil {
 			bucketPolicy = string(policyData)
+		} else if !errors.Is(err, ErrAttributeNotFound) {
+			return fmt.Errorf("failed to fetch bucket policy: %v", err)
 		}
 
 		return nil
@@ -255,6 +259,8 @@ func (h *S3TablesHandler) handleListNamespaces(w http.ResponseWriter, r *http.Re
 		policyData, err := h.getExtendedAttribute(r.Context(), client, bucketPath, ExtendedKeyPolicy)
 		if err == nil {
 			bucketPolicy = string(policyData)
+		} else if !errors.Is(err, ErrAttributeNotFound) {
+			return fmt.Errorf("failed to fetch bucket policy: %v", err)
 		}
 
 		return nil
@@ -425,6 +431,8 @@ func (h *S3TablesHandler) handleDeleteNamespace(w http.ResponseWriter, r *http.R
 		policyData, err := h.getExtendedAttribute(r.Context(), client, bucketPath, ExtendedKeyPolicy)
 		if err == nil {
 			bucketPolicy = string(policyData)
+		} else if !errors.Is(err, ErrAttributeNotFound) {
+			return fmt.Errorf("failed to fetch bucket policy: %v", err)
 		}
 
 		return nil