feat: onboarding trial flow, Google sign-in, dark mode hotspot fixes

- Move trial creation from auth hook to dedicated /subscriptions/trial endpoint
  with eligibility checks (3-day Full Paket trial)
- Add animated onboarding progress (Remotion) with confetti on completion
- Register redirects to subscription page with welcome flow
- Add Google social login/signup support with config injection
- Improve hotspot overlay visibility in dark mode
- Show "Panele Git" on landing page when authenticated
- Turkish translations for API error messages
- Add toast utility wrapper, UUID generation for auth IDs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/config/src/index.ts

@@ -13,6 +13,9 @@ export const envSchema = z.object({
   BETTER_AUTH_SECRET: z.string().min(32),
   BETTER_AUTH_URL: z.string().url(),
 
+  GOOGLE_CLIENT_ID: z.string().optional(),
+  GOOGLE_CLIENT_SECRET: z.string().optional(),
+
   MINIO_ENDPOINT: z.string(),
   MINIO_ACCESS_KEY: z.string(),
   MINIO_SECRET_KEY: z.string(),