Merge remote-tracking branch 'origin/master' into gitea/feature/end

Resolved conflicts taking origin/master (v0.5.55) as canonical, with local
features re-applied:
- runtime log level (LOG_LEVEL env + dashboard Settings → Logging, applied
  immediately and persisted across restarts)
- free/noAuth provider enable/disable toggle via providerStrategies.enabled
- parallel model testing (Test All Models / Test Selected Keys)

open-sse/providers/registry/searxng.js

@@ -1,3 +1,5 @@
+import { SEARXNG_URL } from "../../config/runtimeConfig.js";
+
 export default {
   id: "searxng",
   alias: "searxng",
@@ -15,7 +17,7 @@ export default {
   ],
   noAuth: true,
   searchConfig: {
-    baseUrl: "http://localhost:8888/search",
+    baseUrl: SEARXNG_URL,
     method: "GET",
     authType: "none",
     authHeader: "none",