feat(onboarding): skippable avatar with first-match prompt and usage-reason pack picks

Lets new users skip the onboarding avatar step and instead defers the ask
to a lightweight, dismissible prompt shown once after the couple's first
match. Also personalizes the home screen's first pack recommendation using
the usage_reason already collected during onboarding, which now round-trips
through GET /v1/me.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/mobile/src/lib/analytics.ts

@@ -257,6 +257,10 @@ export const Events = {
   // Profile events
   profileUpdated: (fields: string[]) => logEvent("profile_updated", { fields: fields.join(",") }),
   avatarUploaded: () => logEvent("avatar_uploaded"),
+  avatarSkipped: () => logEvent("avatar_skipped"),
+  avatarPromptShown: (source: string) => logEvent("avatar_prompt_shown", { source }),
+  avatarPromptAccepted: (source: string) => logEvent("avatar_prompt_accepted", { source }),
+  avatarPromptDismissed: (source: string) => logEvent("avatar_prompt_dismissed", { source }),
 
   // Notification events
   notificationPermissionGranted: () => logEvent("notification_permission_granted"),

apps/mobile/src/lib/avatarPromptSeen.ts

@@ -0,0 +1,54 @@
+import * as SecureStore from "expo-secure-store";
+import { Platform } from "react-native";
+
+const STORAGE_KEY_PREFIX = "avatar_prompt_seen";
+
+const buildKey = (userId: string): string => `${STORAGE_KEY_PREFIX}_${userId}`;
+
+async function getStorage(key: string): Promise<boolean> {
+    try {
+        let data: string | null = null;
+
+        if (Platform.OS === "web") {
+            if (typeof window !== "undefined" && typeof window.localStorage !== "undefined") {
+                data = window.localStorage.getItem(key);
+            }
+        } else {
+            data = await SecureStore.getItemAsync(key);
+        }
+
+        return data === "true";
+    } catch (error) {
+        console.error("Error reading avatar prompt state:", error);
+    }
+    return false;
+}
+
+async function setStorage(key: string, seen: boolean): Promise<void> {
+    try {
+        const data = seen ? "true" : "false";
+
+        if (Platform.OS === "web") {
+            if (typeof window !== "undefined" && typeof window.localStorage !== "undefined") {
+                window.localStorage.setItem(key, data);
+            }
+        } else {
+            await SecureStore.setItemAsync(key, data);
+        }
+    } catch (error) {
+        console.error("Error saving avatar prompt state:", error);
+    }
+}
+
+/**
+ * Whether this user has already been shown the deferred avatar prompt (at the
+ * first-match moment), regardless of whether they added a photo or dismissed it.
+ * The prompt is shown at most once per user.
+ */
+export async function hasSeenAvatarPrompt(userId: string): Promise<boolean> {
+    return getStorage(buildKey(userId));
+}
+
+export async function markAvatarPromptSeen(userId: string): Promise<void> {
+    await setStorage(buildKey(userId), true);
+}