There are also a lot of small bug fixes found when testing lots of things end-to-end for the first time and some cleanup now it's integrated with real CA code.
- Includes some bug fixes for previous `api` work and `agent` that weren't tested
- Needed somewhat pervasive changes to support hash based blocking - some TODOs left in our watch toolchain that will explicitly fail on hash-based watches.
- Integration into `connect` is partially done here but still WIP
- register endpoints with supported methods
- support OPTIONS requests, indicating supported methods
- extract method validation (error 405) from individual endpoints
- on 405 where multiple methods are allowed, create a single Allow
header with comma-separated values, not multiple Allow headers.