fix: load claude models directly from provider

Claude's model catalog changes quickly enough that a shared three-day cache can
leave users selecting stale defaults or missing newly available model aliases.
Route Claude model lookups through the provider every time so the UI and slash
commands reflect the current provider result instead of an old disk snapshot.

Keep the static fallback catalog aligned with the latest Claude defaults so the
provider still has a sensible response when live discovery is unavailable.

server/modules/providers/services/provider-models.service.ts

@@ -17,6 +17,7 @@ import { readProviderSessionActiveModelChange } from '@/shared/utils.js';
 
 export const PROVIDER_MODELS_CACHE_TTL_MS = 3 * 24 * 60 * 60 * 1000;
 const PROVIDER_MODELS_CACHE_VERSION = 1;
+const UNCACHED_PROVIDERS = new Set<LLMProvider>(['claude']);
 
 type ProviderModelsServiceDependencies = {
   resolveProvider?: (provider: LLMProvider) => Pick<IProvider, 'models'>;
@@ -232,10 +233,42 @@ export const createProviderModelsService = (dependencies: ProviderModelsServiceD
     return request;
   };
 
+  const loadDirectModels = (
+    provider: LLMProvider,
+  ): Promise<ProviderModelsResult> => {
+    const request = resolveProvider(provider).models.getSupportedModels()
+      .then((models) => {
+        const currentTime = now();
+        return {
+          models,
+          cache: {
+            updatedAt: new Date(currentTime).toISOString(),
+            expiresAt: new Date(currentTime).toISOString(),
+            source: 'fresh' as const,
+          },
+        };
+      })
+      .finally(() => {
+        pendingRequests.delete(provider);
+      });
+
+    pendingRequests.set(provider, request);
+    return request;
+  };
+
   const getProviderModels = async (
     provider: LLMProvider,
     options: ProviderModelsOptions = {},
   ): Promise<ProviderModelsResult> => {
+    if (UNCACHED_PROVIDERS.has(provider)) {
+      const pendingRequest = pendingRequests.get(provider);
+      if (pendingRequest) {
+        return pendingRequest;
+      }
+
+      return loadDirectModels(provider);
+    }
+
     if (options.bypassCache) {
       const pendingRequest = pendingRequests.get(provider);
       if (pendingRequest) {