fix: harden audit durability and fallback config writes

lib/config-store.js

@@ -611,6 +611,19 @@ class ConfigStore {
     });
   }
 
+  saveFallbackLogPath(logFilePath) {
+    const snapshot = String(logFilePath || '').trim();
+    return this._enqueueWrite(() => {
+      const current = this.load();
+      current.globalSettings = {
+        ...(current.globalSettings || {}),
+        logFilePath: snapshot
+      };
+      this._guardHosters(current, false);
+      return this._commit(current);
+    });
+  }
+
   saveRendererGlobalSettings(globalSettings) {
     const snapshot = this._clone(globalSettings || {});
     return this._enqueueWrite(() => {