recommend.js: probe fresh when all cached providers are invalid_key

invalid_key (HTTP 401) can be transient during key rotation or
temporary API issues — unlike rejected/exhausted which are stable
budget states. When cache shows all chain providers as invalid_key,
bypass cache and probe fresh so recovery is immediate instead of
waiting for the 20-minute TTL to expire.

recommend.js

@@ -50,7 +50,18 @@ async function getProviderData() {
   // Try fresh cache first (within 20 minutes from monitor.js runs)
   const cached = getCachedRun(20);
   if (cached && cached.providers) {
-    return { source: 'cache', providers: cached.providers };
+    // Cache hit — but check if all chain members are invalid_key
+    // If so, probe fresh: invalid_key can be transient (API 401s during key rotation)
+    // vs. rejected/exhausted which are stable budget states worth caching
+    const chainProviders = PROVIDER_CHAIN
+      .map(name => cached.providers[name])
+      .filter(Boolean);
+    const allInvalidOrMissing = chainProviders.length === 0 ||
+      chainProviders.every(p => p.status === 'invalid_key' || p.status === 'error');
+    if (!allInvalidOrMissing) {
+      return { source: 'cache', providers: cached.providers };
+    }
+    // All invalid — fall through to fresh probe
   }
 
   // No cache — probe Teams providers directly (no full monitor run, targeted probes only)