* security(web): sanitize WhatsApp accountId to prevent path traversal
Apply normalizeAccountId() from routing/session-key to
resolveDefaultAuthDir() so that malicious config values like
"../../../etc" cannot escape the intended auth directory.
Fixes#2692
* fix(web): check sanitized segment instead of full path in Windows test
* style(web): fix oxfmt formatting in accounts test
Leszek Szpunar