replace gmail resync with Gmail REST API, remove mbsync dependency

First sync still uses IMAP with app password. Subsequent syncs use
Gmail API history.list + messages.get with OAuth for faster, more
reliable incremental sync. Dispatch gmail-sync handler for gmail
accounts instead of generic email-sync. Show sync button for synced
accounts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/apps/officer-web/Screens/Dashboard/Settings/IntegrationsSettings/EmailAccounts.tsx

@@ -210,7 +210,7 @@ export const EmailAccounts = () => {
                   {account.status === 'queued' && (
                     <span className="text-xs text-duck-dark/50 dark:text-foreground/50">Waiting...</span>
                   )}
-                  {account.status === 'connected' && (
+                  {(account.status === 'connected' || account.status === 'synced') && (
                     <Button
                       type="button"
                       variant="outline"
@@ -224,7 +224,7 @@ export const EmailAccounts = () => {
                       ) : (
                         <RefreshCw className="h-3 w-3" />
                       )}
-                      Initial Sync
+                      Sync
                     </Button>
                   )}
                   <button