chore: add MCP sync marker

.vscode/mcp.json

@@ -1,4 +1,5 @@
 {
+  "mcp": {
     "inputs": [
       {
         "type": "promptString",
@@ -26,5 +27,5 @@
         }
       }
     }
-  
+  }
 }

MCP_SYNC.md

@@ -0,0 +1,7 @@
+# MCP Sync
+
+This file was added by Gitea MCP to mark that the `dev-feature-mcp` branch was created and a sync commit was made.
+
+- created_by: mcp_agent
+- date: 2025-11-19
+- purpose: sync demo frontend login files via MCP