Build, test and release on the club Gitea

A Forgejo workflow builds and tests every push and pull request on the
club's docker runner. A v* tag also assembles the plugin zip, checks it
with OpenAC's own plugin checker, and publishes a Gitea release with the
zip, its checksum and plugin.json.

The checker refused the manifest: both permission notes were over the
launcher's 120-character limit. They are shorter now.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/OpenAC.MosswartMassacre/plugin.json

@@ -9,7 +9,7 @@
   "minHostVersion": "0.1.19",
   "capabilitiesVersion": 1,
   "capabilities": [
-    { "name": "network", "note": "Streams telemetry, vitals, chat, inventory and stats to the Mosswart Overlord backend, and receives shared vitals and chat-box commands from it." },
-    { "name": "chat", "note": "Reads chat for kills, rares and combat stats, forwards it to the backend, and runs commands typed into the Overlord chat box." }
+    { "name": "network", "note": "Streams stats, vitals, chat and inventory to Mosswart Overlord, and receives shared vitals and commands from it." },
+    { "name": "chat", "note": "Reads chat for kills, rares and combat stats, forwards it to Overlord, and runs commands sent from its chat box." }
   ]
 }