fix: address code review findings for fileset feature

- Use sqlb.set() instead of set_str() for boolean is_fileset field
  to avoid quoting (SET is_fileset = TRUE not 'TRUE')
- Add JSDoc comment to isFilesetResource explaining it matches
  children inside .fileset/ directories, not the directory itself
- Update OpenAPI spec for file_resource_type_to_file_ext_map endpoint
  to document the new response schema with format_extension and
  is_fileset fields

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/windmill-api/openapi.yaml

@@ -5244,10 +5244,19 @@ paths:
         - $ref: "#/components/parameters/WorkspaceId"
       responses:
         "200":
-          description: map from resource type to file ext
+          description: map from resource type to file resource info
           content:
             application/json:
-              schema: {}
+              schema:
+                type: object
+                additionalProperties:
+                  type: object
+                  properties:
+                    format_extension:
+                      type: string
+                      nullable: true
+                    is_fileset:
+                      type: boolean
 
   /w/{workspace}/resources/type/delete/{path}:
     delete:

backend/windmill-store/src/resources.rs

@@ -1517,7 +1517,7 @@ async fn update_resource_type(
         sqlb.set_str("description", ndesc);
     }
     if let Some(is_fileset) = ns.is_fileset {
-        sqlb.set_str("is_fileset", if is_fileset { "TRUE" } else { "FALSE" });
+        sqlb.set("is_fileset", if is_fileset { "TRUE" } else { "FALSE" });
     }
     sqlb.set_str("edited_at", "now()");
     let sql = sqlb.sql().map_err(|e| Error::internal_err(e.to_string()))?;

cli/src/utils/utils.ts

@@ -154,6 +154,7 @@ export function isFileResource(path: string): boolean {
   );
 }
 
+/** Matches children inside a .fileset/ directory, not the directory itself. */
 export function isFilesetResource(path: string): boolean {
   return path.includes(".fileset/") || path.includes(".fileset\\");
 }