fix(gitea): correct issue auto-close gotcha, drop unused tool

The gotcha claimed Gitea never auto-closes issues on merge. Confirmed
empirically (issue #63 / PR #64) that a regular merge preserving an
original commit's closing keyword does auto-close — only squash merges
(this skill's default) are unreliable. Also drops search_issues from
allowed-tools since no dispatch route calls it.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

plugins/bin/plugin.json

@@ -12,5 +12,5 @@
   "skills": [
     "skills/"
   ],
-  "version": "1.0.4"
+  "version": "1.0.5"
 }