feat: add web campaign links — capture, auth integration, bonus UI

- Add campaign.ts utility (capture from URL, localStorage with TTL, validation)
- Pass campaign_slug in all auth API methods (telegram, widget, email, oauth)
- Consume slug in auth store login methods, set pendingCampaignBonus state
- Add CampaignBonusNotifier component (toast on bonus, mounted in AppShell)
- Show web_link alongside bot deep_link in AdminCampaignStats
- Add CampaignBonusInfo type with union bonus_type
- Fix VerifyEmail: ref guard against StrictMode double-fire, setTimeout cleanup
- Fix AdminCampaignStats: setTimeout refs with cleanup, i18n-aware locale
- Wrap all localStorage access in try/catch (Safari private browsing safety)
- Add campaignBonus translations (ru/en/fa/zh)

src/utils/campaign.ts

@@ -0,0 +1,74 @@
+const CAMPAIGN_KEY = 'campaign_slug';
+const CAMPAIGN_TTL_KEY = 'campaign_slug_ttl';
+const TTL_MS = 24 * 60 * 60 * 1000; // 24 hours
+const SLUG_PATTERN = /^[a-zA-Z0-9_-]{1,64}$/;
+
+/**
+ * Get valid slug from localStorage, clearing expired entries.
+ */
+function getValidSlug(): string | null {
+  try {
+    const slug = localStorage.getItem(CAMPAIGN_KEY);
+    if (!slug) return null;
+
+    const ttl = localStorage.getItem(CAMPAIGN_TTL_KEY);
+    if (!ttl || Number.isNaN(Number(ttl)) || Date.now() > Number(ttl)) {
+      localStorage.removeItem(CAMPAIGN_KEY);
+      localStorage.removeItem(CAMPAIGN_TTL_KEY);
+      return null;
+    }
+
+    return slug;
+  } catch {
+    return null;
+  }
+}
+
+function clearSlug(): void {
+  try {
+    localStorage.removeItem(CAMPAIGN_KEY);
+    localStorage.removeItem(CAMPAIGN_TTL_KEY);
+  } catch {
+    // localStorage unavailable
+  }
+}
+
+/**
+ * Capture campaign slug from URL query param, store in localStorage with TTL,
+ * and clean the URL.
+ */
+export function captureCampaignFromUrl(): void {
+  try {
+    const params = new URLSearchParams(window.location.search);
+    const slug = params.get('campaign');
+    if (!slug || !SLUG_PATTERN.test(slug)) return;
+
+    localStorage.setItem(CAMPAIGN_KEY, slug);
+    localStorage.setItem(CAMPAIGN_TTL_KEY, String(Date.now() + TTL_MS));
+
+    // Clean URL
+    params.delete('campaign');
+    const newSearch = params.toString();
+    const newUrl =
+      window.location.pathname + (newSearch ? `?${newSearch}` : '') + window.location.hash;
+    window.history.replaceState(null, '', newUrl);
+  } catch {
+    // localStorage or history API unavailable
+  }
+}
+
+/**
+ * Consume (get + clear) the stored campaign slug. One-time use during auth.
+ */
+export function consumeCampaignSlug(): string | null {
+  const slug = getValidSlug();
+  if (slug) clearSlug();
+  return slug;
+}
+
+/**
+ * Read stored campaign slug without clearing it (for email registration flow).
+ */
+export function getPendingCampaignSlug(): string | null {
+  return getValidSlug();
+}