Email library: await _loadAccounts before loading emails

After dropping the 'Default' chip, _loadAccounts started setting
state._libAccountId asynchronously while _loadEmails fired in parallel
with the still-null id. The list request was going out with no
account_id (so the server defaulted) while subsequent per-email reads
used the explicit id set after _loadAccounts resolved — back to the
same desync the chip-removal was meant to fix.

Sequence them: await _loadAccounts first, then kick off the folders /
reminders / emails fetches. The list always carries the right
account_id from the very first call.

static/js/emailLibrary.js

@@ -1321,10 +1321,15 @@ export function openEmailLibrary(opts = {}) {
   document.addEventListener('keydown', state._libEscHandler, true);
 
   _renderAccountsLoading();
-  _loadAccounts();
-  _loadFolders();
-  _loadEmailReminderBellVisibility();
-  _loadEmails();
+  // Await accounts before loading emails so the list request carries the
+  // right account_id from the very first fetch (now that we auto-select
+  // an explicit account instead of relying on a 'Default' chip).
+  (async () => {
+    await _loadAccounts();
+    _loadFolders();
+    _loadEmailReminderBellVisibility();
+    _loadEmails();
+  })();
 }
 
 async function _loadAccounts() {