fix(auth): detect HTTPS via X-Forwarded-Proto for SameSite=None cookies, fix AuthGuard null overwrite

- Cookie SameSite now dynamic: None;Secure when behind HTTPS proxy, Lax otherwise
- AuthGuard useEffect no longer overwrites Zustand store with null from background refetch
- AuthInitializer: add staleTime 30s

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

apps/api/src/lib/auth.ts

@@ -28,14 +28,26 @@ function hashToken(token: string) {
   return createHash('sha256').update(`${env.sessionSecret}:${token}`).digest('hex');
 }
 
-export function createSessionCookie(token: string) {
+function isSecureRequest(headers?: { get(name: string): string | null }) {
+  if (env.secureCookies) return true;
+  // Detect HTTPS behind proxy (X-Forwarded-Proto)
+  const proto = headers?.get('x-forwarded-proto');
+  if (proto === 'https') return true;
+  return false;
+}
+
+function buildSameSite(headers?: { get(name: string): string | null }) {
+  return isSecureRequest(headers) ? 'SameSite=None; Secure' : 'SameSite=Lax';
+}
+
+export function createSessionCookie(token: string, headers?: { get(name: string): string | null }) {
   const maxAge = 60 * 60 * 24 * 30;
-  const sameSite = env.secureCookies ? 'SameSite=None; Secure' : 'SameSite=Lax';
+  const sameSite = buildSameSite(headers);
   return `${sessionCookieName}=${token}; HttpOnly; Path=/; ${sameSite}; Max-Age=${maxAge}`;
 }
 
-export function clearSessionCookie() {
-  const sameSite = env.secureCookies ? 'SameSite=None; Secure' : 'SameSite=Lax';
+export function clearSessionCookie(headers?: { get(name: string): string | null }) {
+  const sameSite = buildSameSite(headers);
   return `${sessionCookieName}=; HttpOnly; Path=/; ${sameSite}; Max-Age=0`;
 }
 

apps/api/src/routes/auth.ts

@@ -38,7 +38,7 @@ export const authRoutes = new Elysia({ prefix: '/api/v1/auth' })
       features: getAuthFeatures(),
     };
   })
-  .post('/register', async ({ body, set }) => {
+  .post('/register', async ({ body, set, request }) => {
     const req = body as Partial<RegisterRequest> | undefined;
     const email = normalizeEmail(req?.email);
     const name = normalizeName(req?.name);
@@ -62,7 +62,7 @@ export const authRoutes = new Elysia({ prefix: '/api/v1/auth' })
 
       const user = inserted[0];
       const token = await createSession(user.id);
-      set.headers['Set-Cookie'] = createSessionCookie(token);
+      set.headers['Set-Cookie'] = createSessionCookie(token, request.headers);
 
       authCounter.labels('register', 'true').inc();
 
@@ -79,7 +79,7 @@ export const authRoutes = new Elysia({ prefix: '/api/v1/auth' })
       return serviceUnavailable('Database unavailable');
     }
   })
-  .post('/login', async ({ body, set }) => {
+  .post('/login', async ({ body, set, request }) => {
     const req = body as Partial<AuthRequest> | undefined;
     const email = normalizeEmail(req?.email);
 
@@ -98,7 +98,7 @@ export const authRoutes = new Elysia({ prefix: '/api/v1/auth' })
       }
 
       const token = await createSession(user.id);
-      set.headers['Set-Cookie'] = createSessionCookie(token);
+      set.headers['Set-Cookie'] = createSessionCookie(token, request.headers);
 
       authCounter.labels('login', 'true').inc();
 
@@ -116,8 +116,9 @@ export const authRoutes = new Elysia({ prefix: '/api/v1/auth' })
     }
   })
   .post('/logout', async ({ request, set }) => {
-    await deleteSession(readSessionToken(request.headers.get('cookie')));
-    set.headers['Set-Cookie'] = clearSessionCookie();
+    const cookieHeader = request.headers.get('cookie');
+    await deleteSession(readSessionToken(cookieHeader));
+    set.headers['Set-Cookie'] = clearSessionCookie(request.headers);
     return { ok: true };
   })
   .get('/google', ({ set }) => {