fix(auth): migrate tokens from localStorage to httpOnly cookies + CSRF hardening

Backend:
- Auth controller sets httpOnly secure cookies (access_token, refresh_token, goodgo_authenticated) on login/register/refresh
- JWT strategy reads token from cookie first, falls back to Authorization header
- Added POST /auth/logout to clear auth cookies
- Added POST /auth/exchange-token for OAuth callback token-to-cookie exchange
- Refresh endpoint reads refresh_token from cookie (body fallback for backwards compat)
- CSRF middleware excludes auth endpoints (login, register, refresh, exchange-token, logout)

Frontend:
- Removed all localStorage token storage (goodgo_tokens key)
- Removed authGet/authPost/authPatch helpers from api-client (tokens sent via cookies)
- All API calls use credentials:'include' for cookie-based auth
- Updated auth-store: no more token state, uses isAuthenticated flag from cookie
- Updated admin-api, listings-api to remove explicit token parameters
- Updated all pages (admin dashboard, users, KYC, moderation, listings) to remove token passing
- OAuth callbacks use exchange-token endpoint to convert URL tokens to cookies
- Auth provider simplified (no client-side cookie management needed)

Security improvements:
- JWT no longer accessible via JavaScript (XSS-safe)
- Refresh token scoped to /auth path only
- Server-side goodgo_authenticated cookie with SameSite=Lax
- Access token cookie with SameSite=Strict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/app/auth/callback/google/page.tsx

@@ -30,11 +30,11 @@ export default function GoogleCallbackPage() {
       return;
     }
 
-    handleOAuthCallback({
+    handleOAuthCallback(
       accessToken,
       refreshToken,
-      expiresIn: expiresIn ? Number(expiresIn) : 900,
-    })
+      expiresIn ? Number(expiresIn) : 900,
+    )
       .then(() => {
         const redirect = searchParams.get('redirect') || '/dashboard';
         router.replace(redirect);