Hotfix-cant-run-tools-when-no-credits (#5955)

Tested:
* Can sign in on saas -> can run local tools with or without credits->
can run saas only tools (if credits) -> can't run saas only tools
without credits
* Can sign in self-hosted -> can run all tools on remote if available ->
can run local when self-hosted unavailable

Clouds show on saas tools when connected
Tools are disabled when connected to self-hosted but cannot find server.
You also get banner


#cantwaitforplaywritetests

frontend/src/desktop/hooks/useConversionCloudStatus.ts

@@ -100,14 +100,18 @@ export function useConversionCloudStatus(): ConversionStatus {
         pairs.map(async ([fromExt, toExt, endpointName]) => {
           const key = `${fromExt}-${toExt}`;
           try {
-            const combined = await endpointAvailabilityService.checkEndpointCombined(
+            // In SaaS mode, everything is available (locally or via cloud routing).
+            // Only check local support to determine willUseCloud — the same approach
+            // used by useMultipleEndpointsEnabled's SaaS enhancement.
+            const availableLocally = await endpointAvailabilityService.isEndpointSupportedLocally(
               endpointName,
               tauriBackendService.getBackendUrl()
             );
-            return { key, isAvailable: combined.isAvailable, willUseCloud: combined.willUseCloud, localOnly: combined.localOnly };
+            return { key, isAvailable: true, willUseCloud: !availableLocally, localOnly: false };
           } catch (error) {
             console.error(`[useConversionCloudStatus] Endpoint check failed for ${key}:`, error);
-            return { key, isAvailable: false, willUseCloud: false, localOnly: false };
+            // On error, assume available via cloud (safe default in SaaS mode)
+            return { key, isAvailable: true, willUseCloud: true, localOnly: false };
           }
         })
       );

frontend/src/desktop/hooks/useCreditCheck.ts

@@ -4,6 +4,7 @@ import { useSaaSBilling } from '@app/contexts/SaasBillingContext';
 import { useSaaSMode } from '@app/hooks/useSaaSMode';
 import { getToolCreditCost } from '@app/utils/creditCosts';
 import { CREDIT_EVENTS } from '@app/constants/creditEvents';
+import { operationRouter } from '@app/services/operationRouter';
 import type { ToolId } from '@app/types/toolId';
 
 /**
@@ -15,15 +16,27 @@ import type { ToolId } from '@app/types/toolId';
  * Returns null when the operation is allowed, or an error message string
  * when it should be blocked.
  */
-export function useCreditCheck(operationType?: string) {
+export function useCreditCheck(operationType?: string, endpoint?: string) {
   const billing = useSaaSBilling();
   const isSaaSMode = useSaaSMode();
   const { t } = useTranslation();
 
-  const checkCredits = useCallback(async (): Promise<string | null> => {
+  const checkCredits = useCallback(async (runtimeEndpoint?: string): Promise<string | null> => {
     if (!isSaaSMode) return null; // Credits only apply in SaaS mode, not self-hosted
     if (!billing) return null;
 
+    // If the operation routes to the local backend, no credits are consumed — skip check.
+    // runtimeEndpoint (from params at execution time) takes priority over hook-level endpoint.
+    const ep = runtimeEndpoint ?? endpoint;
+    if (ep) {
+      try {
+        const willUseSaaS = await operationRouter.willRouteToSaaS(ep);
+        if (!willUseSaaS) return null;
+      } catch {
+        // If routing check fails, fall through to credit check as a safe default.
+      }
+    }
+
     const { creditBalance, loading } = billing;
     const requiredCredits = getToolCreditCost(operationType as ToolId);
 
@@ -44,7 +57,7 @@ export function useCreditCheck(operationType?: string) {
     }
 
     return null;
-  }, [billing, isSaaSMode, operationType, t]);
+  }, [billing, isSaaSMode, operationType, endpoint, t]);
 
   return { checkCredits };
 }