fix(mobile): lazy env proxy so missing EXPO_PUBLIC vars throw inside React

apps/mobile/lib/env.test.ts

@@ -0,0 +1,30 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+describe('mobile env (lazy proxy)', () => {
+  beforeEach(() => {
+    vi.resetModules();
+    delete process.env.EXPO_PUBLIC_SUPABASE_URL;
+    delete process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY;
+    delete process.env.EXPO_PUBLIC_AUTH_REDIRECT_URL;
+  });
+
+  it('importing the module does NOT throw when required vars are missing', async () => {
+    await expect(import('./env')).resolves.toBeTruthy();
+  });
+
+  it('reading a property with no env set throws a clear error', async () => {
+    const mod = await import('./env');
+    expect(() => mod.env.supabaseUrl).toThrowError(
+      /Missing required env var EXPO_PUBLIC_SUPABASE_URL/,
+    );
+  });
+
+  it('reading a property after setting env returns the value and memoises', async () => {
+    process.env.EXPO_PUBLIC_SUPABASE_URL = 'https://example.supabase.co';
+    process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY = 'anon-123';
+    const mod = await import('./env');
+    expect(mod.env.supabaseUrl).toBe('https://example.supabase.co');
+    expect(mod.env.supabaseAnonKey).toBe('anon-123');
+    expect(mod.env.authRedirectUrl).toBe('netralax://auth/callback');
+  });
+});