fix(plugins): address review feedback for Matrix recovery paths (#52899)

1. Narrow loadConfigForInstall() to catch only INVALID_CONFIG errors,
   letting real failures (fs permission, OOM) propagate.
2. Assert allow array is properly cleaned in stale-cleanup test.
3. Add comment clarifying version-resolution is already addressed via
   the shared VERSION constant.
4. Run cleanStaleMatrixPluginConfig() during install so
   persistPluginInstall() → writeConfigFile() does not fail validation
   on stale Matrix load paths.

src/plugins/runtime/index.ts

@@ -184,6 +184,8 @@ export type CreatePluginRuntimeOptions = {
 export function createPluginRuntime(_options: CreatePluginRuntimeOptions = {}): PluginRuntime {
   const mediaUnderstanding = createRuntimeMediaUnderstandingFacade();
   const runtime = {
+    // Sourced from the shared OpenClaw version resolver (#52899) so plugins
+    // always see the same version the CLI reports, avoiding API-version drift.
     version: VERSION,
     config: createRuntimeConfig(),
     agent: createRuntimeAgent(),