fix: 7 bug fixes + port config with auto-restart

- HTTPException import added (was causing 500 on missing dashboard)
- game_manager.remove_plugin() restored (was AttributeError)
- api.js checks HTTP status codes, fails fast on errors
- sidebar game highlight only matches selected gameId
- scene resize handler uses stored canvas dims (was NaN)
- forwarder socket properly closed on listener stop
- telemetry port: use_unified_port toggle, off = per-game port, auto-restart on switch

server/game_manager.py

@@ -130,6 +130,20 @@ class GamePluginManager:
         self._discover()
         self._parser_cache.clear()
 
+    def remove_plugin(self, plugin_id: str) -> bool:
+        self._discover()
+        gp = self._plugins.get(plugin_id)
+        if gp and gp.is_builtin:
+            logger.warning("Cannot remove builtin plugin: %s", plugin_id)
+            return False
+        dest_dir = USER_DIR / plugin_id
+        if dest_dir.exists():
+            shutil.rmtree(dest_dir)
+            self._discover()
+            logger.info("Plugin removed: %s", plugin_id)
+            return True
+        return False
+
     def install_plugin_zip(self, zip_data: bytes) -> bool:
         try:
             with zipfile.ZipFile(io.BytesIO(zip_data), 'r') as zf: