feat: add fileset resource type support

Add a new "fileset" resource type that represents a collection of files
stored as a relpath→content map. This enables resource types to manage
multiple files (e.g., config directories, template sets) instead of just
a single file.

Backend:
- Add is_fileset column to resource_type table
- Update CRUD operations and workspace duplication to handle is_fileset
- Add integration tests for fileset resource types

Frontend:
- Add FilesetEditor component with file explorer + Monaco editor
- Extract shared FileExplorer component from RawAppSidebar (dedup)
- Add fileset toggle to EditableSchemaWrapper
- Show fileset editor in ResourceEditor and ApiConnectForm
- Show folder icon for fileset resource types in IconedResourceType

CLI:
- Support fileset resources in sync pull (expand to .fileset/ directory)
- Support fileset resources in sync push (reconstruct from directory)
- Handle !inline_fileset YAML tag in resource resolution

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

cli/src/core/specific_items.ts

@@ -1,6 +1,6 @@
 import { minimatch } from "minimatch";
 import { getCurrentGitBranch, isGitRepository } from "../utils/git.ts";
-import { isFileResource } from "../utils/utils.ts";
+import { isFileResource, isFilesetResource } from "../utils/utils.ts";
 import { SyncOptions } from "./conf.ts";
 import { TRIGGER_TYPES } from "../types.ts";
 
@@ -165,7 +165,7 @@ export function isItemTypeConfigured(path: string, specificItems: SpecificItemsC
     return specificItems.settings !== undefined;
   }
 
-  if (isFileResource(path)) {
+  if (isFileResource(path) || isFilesetResource(path)) {
     return specificItems.resources !== undefined;
   }
 
@@ -219,6 +219,14 @@ export function isSpecificItem(path: string, specificItems: SpecificItemsConfig
     }
   }
 
+  if (isFilesetResource(path)) {
+    const basePathMatch = path.match(/^(.+?)\.fileset[/\\]/);
+    if (basePathMatch && specificItems.resources) {
+      const basePath = basePathMatch[1] + '.resource.yaml';
+      return matchesPatterns(basePath, specificItems.resources);
+    }
+  }
+
   return false;
 }