## Why
MITM hooks authorize requests before the upstream server parses them. Paths that
can be decoded or normalized to a different resource must not match an allowed
path, and hosts that require MITM inspection must not bypass it through the
plain HTTP proxy path.
## What changed
- Reject ambiguous hook paths, including traversal segments, backslashes,
malformed percent encodings, and encoded separators or percent signs.
- Block plain HTTP proxy requests for hosts whose policy always requires MITM,
recording the decision as `mitm_required`.
## Testing
- Cover safe and ambiguous path forms, encoded traversal through repository
allowlists, and absolute-form HTTPS requests sent to the HTTP proxy.
GitOrigin-RevId: 8812a980ac64a97cbac3a237376d29be5ded9220