fix(codex): prevent infinite loop when fetching models on settings screen

When Codex is not connected/authenticated, the /api/codex/models endpoint
returns 503. The fetchCodexModels function had no cooldown after failures,
causing infinite retries when navigating to the Settings screen.

Added codexModelsLastFailedAt state to track failed fetch attempts and
skip retries for 30 seconds after a failure. This prevents the infinite
loop while still allowing periodic retry attempts.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/ui/src/store/app-store.ts

@@ -689,6 +689,7 @@ export interface AppState {
   codexModelsLoading: boolean;
   codexModelsError: string | null;
   codexModelsLastFetched: number | null;
+  codexModelsLastFailedAt: number | null;
 
   // Pipeline Configuration (per-project, keyed by project path)
   pipelineConfigByProject: Record<string, PipelineConfig>;
@@ -1286,6 +1287,7 @@ const initialState: AppState = {
   codexModelsLoading: false,
   codexModelsError: null,
   codexModelsLastFetched: null,
+  codexModelsLastFailedAt: null,
   pipelineConfigByProject: {},
   worktreePanelVisibleByProject: {},
   showInitScriptIndicatorByProject: {},
@@ -3113,11 +3115,21 @@ export const useAppStore = create<AppState & AppActions>()((set, get) => ({
 
   // Codex Models actions
   fetchCodexModels: async (forceRefresh = false) => {
-    const { codexModelsLastFetched, codexModelsLoading } = get();
+    const { codexModelsLastFetched, codexModelsLoading, codexModelsLastFailedAt } = get();
 
     // Skip if already loading
     if (codexModelsLoading) return;
 
+    // Skip if recently failed (< 30 seconds ago) and not forcing refresh
+    const FAILURE_COOLDOWN = 30000; // 30 seconds
+    if (
+      !forceRefresh &&
+      codexModelsLastFailedAt &&
+      Date.now() - codexModelsLastFailedAt < FAILURE_COOLDOWN
+    ) {
+      return;
+    }
+
     // Skip if recently fetched (< 5 minutes ago) and not forcing refresh
     if (!forceRefresh && codexModelsLastFetched && Date.now() - codexModelsLastFetched < 300000) {
       return;
@@ -3142,12 +3154,14 @@ export const useAppStore = create<AppState & AppActions>()((set, get) => ({
         codexModelsLastFetched: Date.now(),
         codexModelsLoading: false,
         codexModelsError: null,
+        codexModelsLastFailedAt: null, // Clear failure on success
       });
     } catch (error) {
       const errorMessage = error instanceof Error ? error.message : 'Unknown error';
       set({
         codexModelsError: errorMessage,
         codexModelsLoading: false,
+        codexModelsLastFailedAt: Date.now(), // Record failure time for cooldown
       });
     }
   },