gitea_url_matches_host compared every remote authority's port directly
against the configured HTTP(S) API URL's port, which conflated two
unrelated things and normalized default web ports asymmetrically:
- An SSH remote's transport port (e.g. ssh://git@host:2222/...) was
compared against the configured HTTP(S) port, even though the SSH
daemon port has nothing to do with the Gitea HTTP(S) API port.
- An explicit default port on the remote (https://host:443/...) failed
to match an implicit (portless) configured URL, while the inverse
(implicit remote vs. explicit configured) already matched -- the
default-port equivalence was only applied on one side.
Fix get_remote_host() to strip an SSH transport port before it ever
reaches host-match, and make gitea_url_matches_host's default-port
normalization symmetric (":443" https / ":80" http is equivalent to
the implicit form on BOTH sides).
Adds red-first regressions for both repros to
test-pr-review-gitea-comment.sh (extending the #812 harness) and wires
that harness into packages/mosaic's test:framework-shell chain so it
runs under `pnpm test`.
Closes#850
