Refactor registration and dashboard features to support invite codes and Bunny uploads

- Moved registration logic to a new client component for better separation of concerns.
- Integrated invite code requirement based on feature flags in the registration process.
- Enhanced dashboard functionality to conditionally enable Bunny uploads based on feature flags.
- Updated various components and API routes to check for Bunny uploads and Stripe billing feature flags.
- Added new feature flag utilities for managing feature toggles in the application.

lib/feature-flags.ts

@@ -0,0 +1,41 @@
+function readBooleanEnv(name: string, defaultValue: boolean): boolean {
+  const value = process.env[name];
+  if (!value) return defaultValue;
+
+  const normalized = value.trim().toLowerCase();
+  if (normalized === 'true') return true;
+  if (normalized === 'false') return false;
+
+  return defaultValue;
+}
+
+export function isStripeFeatureEnabled() {
+  return readBooleanEnv('OPENFRAME_ENABLE_STRIPE', true);
+}
+
+export function hasStripeConfig() {
+  return Boolean(process.env.STRIPE_SECRET_KEY && process.env.STRIPE_PRICE_ID);
+}
+
+export function isStripeBillingEnabled() {
+  return isStripeFeatureEnabled() && hasStripeConfig();
+}
+
+export function isBunnyUploadsFeatureEnabled() {
+  return readBooleanEnv('OPENFRAME_ENABLE_BUNNY_UPLOADS', true);
+}
+
+export function hasBunnyUploadsConfig() {
+  return Boolean(
+    process.env.BUNNY_STREAM_API_KEY &&
+    (process.env.BUNNY_STREAM_LIBRARY_ID || process.env.NEXT_PUBLIC_BUNNY_STREAM_LIBRARY_ID)
+  );
+}
+
+export function isBunnyUploadsEnabled() {
+  return isBunnyUploadsFeatureEnabled() && hasBunnyUploadsConfig();
+}
+
+export function isInviteCodeRequired() {
+  return readBooleanEnv('OPENFRAME_REQUIRE_INVITE_CODE', true);
+}