Add feature interest buttons to dares and quiz

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

apps/mobile/src/hooks/useFeatureInterest.ts

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+import { useState, useEffect, useCallback } from "react";
+import { supabase } from "../lib/supabase";
+import { useAuthStore } from "../store";
+
+export function useFeatureInterest(featureName: string) {
+    const [isInterested, setIsInterested] = useState(false);
+    const [isLoading, setIsLoading] = useState(true);
+    const [isToggling, setIsToggling] = useState(false);
+    const user = useAuthStore((state) => state.user);
+
+    // Fetch current interest status
+    useEffect(() => {
+        async function fetchInterest() {
+            if (!user?.id) {
+                setIsLoading(false);
+                return;
+            }
+
+            const { data } = await supabase
+                .from("feature_interests")
+                .select("id")
+                .eq("user_id", user.id)
+                .eq("feature_name", featureName)
+                .maybeSingle();
+
+            setIsInterested(!!data);
+            setIsLoading(false);
+        }
+
+        fetchInterest();
+    }, [user?.id, featureName]);
+
+    const toggleInterest = useCallback(async () => {
+        if (!user?.id || isToggling) return;
+
+        setIsToggling(true);
+        const wasInterested = isInterested;
+
+        // Optimistic update
+        setIsInterested(!wasInterested);
+
+        try {
+            if (wasInterested) {
+                // Remove interest
+                const { error } = await supabase
+                    .from("feature_interests")
+                    .delete()
+                    .eq("user_id", user.id)
+                    .eq("feature_name", featureName);
+
+                if (error) throw error;
+            } else {
+                // Add interest
+                const { error } = await supabase
+                    .from("feature_interests")
+                    .insert({
+                        user_id: user.id,
+                        feature_name: featureName,
+                    });
+
+                if (error) throw error;
+            }
+        } catch (error) {
+            console.error("Error toggling feature interest:", error);
+            // Revert on error
+            setIsInterested(wasInterested);
+        } finally {
+            setIsToggling(false);
+        }
+    }, [user?.id, featureName, isInterested, isToggling]);
+
+    return {
+        isInterested,
+        isLoading,
+        isToggling,
+        toggleInterest,
+        isAuthenticated: !!user?.id,
+    };
+}