fix(release): track hooks, workflows, and plugin config in core releases

Add additional-paths to release-please config so changes to hooks/,
workflows/, and .claude-plugin/ trigger core releases. Previously
only packages/core/ was tracked, causing plugin-level fixes to be
silently excluded from releases.

Author: costajohnt

release-please-config.json

@@ -7,6 +7,7 @@
       "bump-minor-pre-major": true,
       "draft": false,
       "prerelease": false,
+      "additional-paths": ["hooks", "workflows", ".claude-plugin"],
       "extra-files": [
         {
           "type": "json",