## Why
Older executors sandbox reads whenever a policy is supplied, even when the policy allows unrestricted reads. This can interfere with loading skills across executor versions.
## What changed
- Omit sandbox contexts from remote read operations when reads are unrestricted and explicit permission paths are valid for the target path convention. Retain contexts that require executor-side path validation.
- Check remote `windows_mxc` support before sending MXC sandbox contexts for reads or capability discovery, returning an update-executor error when unsupported.
## Testing
Add coverage for permission path validation across read operations, unsupported MXC requests, and skill loading over Noise with mismatched app and executor versions, including selected skill roots with capability discovery disabled.
GitOrigin-RevId: 4a2a7ccaa2ba4daac657bd84aea603404452be45
## What changed
- Add a Bazel test rule that runs the shared Noise relay compatibility suite with current or packaged Codex binaries.
- Cover both app-server/exec-server directions for the current build, release `0.149.1`, and the minimum supported release `0.145.0` on Linux x86-64.
- Remove the standalone version-skew download scripts and the protocol constant they used.
## Testing
The new `exec-server-current-version-test`, `exec-server-stable-release-test`, and `exec-server-minimum-release-test` targets exercise the compatibility suite.
GitOrigin-RevId: 6b3b91eea8e05a38bec1fac128afc54f0d654014
Dmitriy Kovalenko