refactor: keep only node class ESSENTIALS_CATEGORY, remove blueprint/subgraph changes

Frontend will own blueprint categorization separately.

app/subgraph_manager.py

@@ -1,9 +1,7 @@
 from __future__ import annotations
 
 from typing import TypedDict
-from typing_extensions import NotRequired
 import os
-import json
 import folder_paths
 import glob
 from aiohttp import web
@@ -33,7 +31,6 @@ class SubgraphEntry(TypedDict):
     Additional info about subgraph; in the case of custom_nodes, will contain nodepack name
     """
     data: str
-    essentials_category: NotRequired[str]
 
 class CustomNodeSubgraphEntryInfo(TypedDict):
     node_pack: str
@@ -104,16 +101,6 @@ class SubgraphManager:
             for file in glob.glob(os.path.join(blueprints_dir, "*.json")):
                 file = file.replace('\\', '/')
                 entry_id, entry = self._create_entry(file, Source.templates, "comfyui")
-                try:
-                    with open(file, 'r', encoding='utf-8') as f:
-                        bp_data = json.load(f)
-                    subgraphs = bp_data.get('definitions', {}).get('subgraphs', [])
-                    if subgraphs:
-                        ec = subgraphs[0].get('essentials_category')
-                        if ec:
-                            entry['essentials_category'] = ec
-                except Exception:
-                    pass
                 subgraphs_dict[entry_id] = entry
 
         self.cached_blueprint_subgraphs = subgraphs_dict