debug: add workflow_dispatch to release workflow for manual testing

Author: mcp-release-bot

.github/workflows/release.yml

@@ -4,6 +4,12 @@ on:
   push:
     tags:
       - 'v*'
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Tag to release (e.g., v0.3.5)'
+        required: true
+        type: string
 
 env:
   PYTHON_VERSION: "3.13"