feat(ui): add dispose instance and rehydrate

Adds a dispose instance action to the instance info view, POSTing to /instance/dispose and rehydrating per-instance stores; also handles server.instance.disposed events and adds danger button styling.

packages/opencode-config/package.json

@@ -4,6 +4,6 @@
   "private": true,
   "license": "MIT",
   "dependencies": {
-    "@opencode-ai/plugin": "1.2.4"
+    "@opencode-ai/plugin": "1.2.6"
   }
-}
+}