add resilient self-plan generation with provider fallback

apps/mobile/src/app/(tabs)/goals.tsx

@@ -203,7 +203,7 @@ export default function GoalsScreen() {
       await Promise.all([refetchRecommendations(), refetchGoals()]);
       Alert.alert(
         "Plan Ready",
-        "Your new AI activity plan has been generated and active goals were added.",
+        "Your new activity plan is ready and active goals were added.",
       );
     } catch (error) {
       const message =