feat: add basic webui

packages/feature-flags/lib/create-flag.ts

@@ -0,0 +1,20 @@
+import { analytics } from '@konobangu/analytics/server';
+import { getSessionFromHeaders } from '@konobangu/auth/server';
+import { unstable_flag as flag } from '@vercel/flags/next';
+
+export const createFlag = (key: string) =>
+  flag({
+    key,
+    defaultValue: false,
+    async decide() {
+      const { userId } = await getSessionFromHeaders();
+
+      if (!userId) {
+        return this.defaultValue as boolean;
+      }
+
+      const isEnabled = await analytics.isFeatureEnabled(key, userId);
+
+      return isEnabled ?? (this.defaultValue as boolean);
+    },
+  });