Two small defensive-hardening changes:
- web/src/components/Markdown.tsx: render links only for http(s)/mailto
schemes; other schemes (javascript:, data:, vbscript:) are dropped to
plain text so a crafted link in rendered content can't execute on click.
- gateway/platforms/wecom_callback.py: parse the untrusted, pre-auth WeCom
callback request body with defusedxml instead of xml.etree, blocking
entity-expansion / billion-laughs (and XXE) on the parse path. defusedxml
is already a dependency (uv.lock); response-building XML in
wecom_crypto.py is unchanged (it is not parsed from untrusted input).
Verified: dashboard typechecks and builds; defusedxml blocks an
entity-expansion payload while valid WeCom envelopes still parse.
5744b17579