## Stack
1. This PR adds MITM hook config and model only.
2. Runtime follow up: #20659 wires hook enforcement into the proxy
request path.
3. User facing config follow up: #18240 moves MITM policy into the
PermissionProfile network tree.
## Why
1. Viyat asked for the original parent PR to be split so reviewers can
inspect the policy model before request behavior changes.
2. This PR gives the proxy a typed MITM hook model, validation, matcher
compilation, permissions TOML plumbing, schema support, and config
tests.
3. This PR deliberately does not change CONNECT or MITM request
handling.
4. Keeping runtime behavior out of this PR makes the review boundary
simple: does the policy model parse, validate, compile, and lower
correctly.
## Summary
1. Add the MITM hook config model and matcher compilation.
2. Validate hosts, methods, paths, query matchers, header matchers,
secret sources, and reserved body matching.
3. Add wildcard matcher support for path, query value, and header value
matching.
4. Add permissions TOML and schema support for flat runtime hook config.
5. Add config loader tests for MITM hook overlay behavior.
## Validation
1. Regenerated the config schema.
2. Ran the network proxy MITM hook unit tests.
3. Ran the core permission profile MITM hook parsing tests.
4. Ran the core config schema fixture test.
5. Ran the scoped Clippy fixer for the network proxy crate.
6. Ran the scoped Clippy fixer for the core crate.
## Notes
1. Runtime enforcement moved to #20659.
2. User facing PermissionProfile TOML shape remains in #18240.
evawong-oai