✨ Add gitea plugin

Ports dirigent's gitea scripts into a self-contained reliquary plugin.
Scripts run via uv with PEP 723 inline deps — no project venv needed.
Gitea connection inferred from `git remote get-url origin` with env-var
overrides; only GITEA_TOKEN is mandatory. Workpad path and tickets
directory are parameterized so the plugin works in any project. Label
set externalized to labels.default.json with project-level override via
.gitea-labels.json.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugins/gitea/.claude-plugin/plugin.json

@@ -0,0 +1,9 @@
+{
+  "name": "gitea",
+  "version": "0.1.0",
+  "description": "Gitea issue integration: fetch/create/list/close tickets, post comments, scaffold labels. Workpad-aware.",
+  "author": {
+    "name": "Gabor Körber",
+    "email": "gab@g4b.org"
+  }
+}