fix(GRO-2652): reset authInitPromise on failure so retry loop actually retries

Previously the initAuth() function set authInitPromise to the async IIFE's
Promise but never cleared it on rejection. The index.ts retry loop called
initAuth() up to 10 times, but on attempt 2+ the check
`if (authInitPromise) { await authInitPromise; return; }` would immediately
re-throw the original rejection without performing a real retry.

Fix: wrap the final `await authInitPromise` in try/catch and reset
authInitPromise = null on error. This allows the index.ts retry loop to
create a fresh attempt on each call after a failure.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/lib/auth.ts

@@ -329,5 +329,10 @@ export async function initAuth(): Promise<void> {
     });
   })();
 
-  await authInitPromise;
+  try {
+    await authInitPromise;
+  } catch (err) {
+    authInitPromise = null; // allow retry on next call
+    throw err;
+  }
 }