fix: resolve all 14 ESLint warnings across the codebase

- Add varsIgnorePattern to no-unused-vars for destructuring patterns
- Fix all react-hooks/exhaustive-deps by adding missing dependencies
- Refactor useAnimatedNumber to use ref instead of stale state closure
- Wrap handleLinkResult in useCallback for stable deps
- Extract OAuth utilities from OAuthCallback.tsx to utils/oauth.ts
- Extract background config utilities to utils/backgroundConfig.ts
- Remove unused catch parameter in GiftSubscription

src/components/TelegramLoginButton.tsx

@@ -103,7 +103,7 @@ export default function TelegramLoginButton({ referralCode }: TelegramLoginButto
       setScriptLoaded(true);
       initTelegramLogin();
     }
-  }, [isOIDC, widgetConfig?.oidc_client_id, widgetConfig?.request_access]);
+  }, [isOIDC, widgetConfig?.oidc_client_id, widgetConfig?.request_access, t]);
 
   // Legacy widget effect (only when NOT OIDC)
   const loginWithTelegramWidget = useAuthStore((s) => s.loginWithTelegramWidget);

src/components/admin/BackgroundEditor.tsx

@@ -2,7 +2,7 @@ import { useState, useCallback, useRef, useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import { brandingApi } from '@/api/branding';
-import { setCachedAnimationConfig } from '@/components/backgrounds/BackgroundRenderer';
+import { setCachedAnimationConfig } from '@/utils/backgroundConfig';
 import type { AnimationConfig } from '@/components/ui/backgrounds/types';
 import { DEFAULT_ANIMATION_CONFIG } from '@/components/ui/backgrounds/types';
 import { BackgroundConfigEditor } from './BackgroundConfigEditor';

src/components/backgrounds/BackgroundRenderer.tsx

@@ -5,57 +5,7 @@ import { brandingApi } from '@/api/branding';
 import type { AnimationConfig, BackgroundType } from '@/components/ui/backgrounds/types';
 import { DEFAULT_ANIMATION_CONFIG } from '@/components/ui/backgrounds/types';
 import { backgroundComponents, prefetchBackground } from '@/components/ui/backgrounds/registry';
-
-const ANIMATION_CACHE_KEY = 'cabinet_animation_config';
-const MAX_CONFIG_JSON_LENGTH = 10_000;
-
-const VALID_TYPES: ReadonlySet<string> = new Set<BackgroundType>([
-  'aurora',
-  'sparkles',
-  'vortex',
-  'shooting-stars',
-  'background-beams',
-  'background-beams-collision',
-  'gradient-animation',
-  'wavy',
-  'background-lines',
-  'boxes',
-  'meteors',
-  'grid',
-  'dots',
-  'spotlight',
-  'ripple',
-  'none',
-]);
-
-function validateConfig(parsed: unknown): AnimationConfig | null {
-  if (typeof parsed !== 'object' || parsed === null || Array.isArray(parsed)) return null;
-  const obj = parsed as Record<string, unknown>;
-  if (typeof obj.enabled !== 'boolean') return null;
-  if (typeof obj.type !== 'string' || !VALID_TYPES.has(obj.type)) return null;
-  if (typeof obj.opacity !== 'number') return null;
-  if (typeof obj.blur !== 'number') return null;
-  if (obj.settings != null && (typeof obj.settings !== 'object' || Array.isArray(obj.settings)))
-    return null;
-  return {
-    enabled: obj.enabled,
-    type: obj.type as BackgroundType,
-    opacity: Math.max(0, Math.min(1, obj.opacity)),
-    blur: Math.max(0, Math.min(50, obj.blur)),
-    settings: (obj.settings as Record<string, unknown>) ?? {},
-    reducedOnMobile: typeof obj.reducedOnMobile === 'boolean' ? obj.reducedOnMobile : true,
-  };
-}
-
-function getCachedConfig(): AnimationConfig | null {
-  try {
-    const cached = localStorage.getItem(ANIMATION_CACHE_KEY);
-    if (!cached || cached.length > MAX_CONFIG_JSON_LENGTH) return null;
-    return validateConfig(JSON.parse(cached));
-  } catch {
-    return null;
-  }
-}
+import { validateConfig, getCachedConfig, setCachedConfig } from '@/utils/backgroundConfig';
 
 // Prefetch the background JS chunk immediately based on localStorage cache.
 const cachedConfig = getCachedConfig();
@@ -63,17 +13,6 @@ if (cachedConfig?.enabled && cachedConfig.type && cachedConfig.type !== 'none')
   prefetchBackground(cachedConfig.type);
 }
 
-function setCachedConfig(config: AnimationConfig) {
-  try {
-    localStorage.setItem(ANIMATION_CACHE_KEY, JSON.stringify(config));
-  } catch {}
-}
-
-export function setCachedAnimationConfig(config: AnimationConfig) {
-  const validated = validateConfig(config);
-  if (validated) setCachedConfig(validated);
-}
-
 function reduceMobileSettings(settings: Record<string, unknown>): Record<string, unknown> {
   const reduced = { ...settings };
   // 75% reduction (divide by 4) instead of 50% — much less GPU work
@@ -94,7 +33,6 @@ function reduceMobileSettings(settings: Record<string, unknown>): Record<string,
   return reduced;
 }
 
-/** Renders the background animation into a portal at document.body */
 function RenderBackground({ config }: { config: AnimationConfig }) {
   const prefersReducedMotion = useMemo(
     () => window.matchMedia('(prefers-reduced-motion: reduce)').matches,
@@ -136,7 +74,6 @@ function RenderBackground({ config }: { config: AnimationConfig }) {
   );
 }
 
-/** BackgroundRenderer that fetches config from the branding API (for authenticated app shell) */
 export function BackgroundRenderer() {
   const { data: config } = useQuery({
     queryKey: ['animation-config'],
@@ -155,7 +92,6 @@ export function BackgroundRenderer() {
   return <RenderBackground config={effectiveConfig} />;
 }
 
-/** StaticBackgroundRenderer that uses a provided config (for public landing pages) */
 export function StaticBackgroundRenderer({ config }: { config: AnimationConfig }) {
   const validated = useMemo(() => validateConfig(config), [config]);
   if (!validated) return null;

src/components/ui/backgrounds/background-beams-collision.tsx

@@ -125,7 +125,7 @@ function CollisionMechanism({
     }, 2000);
 
     return () => clearTimeout(timer);
-  }, [collision.detected]);
+  }, [collision.detected, collision.coordinates]);
 
   return (
     <>