## Why
Executor config reads omitted the startup `features.prefer_mxc` override, so clients could not see the CLI sandbox preference.
## What changed
- Include the explicit CLI `features.prefer_mxc` value in `environmentConfig/read` as a `session-flags` layer, above project config and below legacy managed file and MDM config.
- Retain only this preference from startup overrides.
- Expose `windows_mxc_allowed_by_config` to share MXC eligibility checks after callers resolve the active permission profile.
## Testing
Add CLI and remote executor coverage for preference propagation and filtering, plus a unit test verifying that both legacy managed config sources retain precedence.
GitOrigin-RevId: 5ac6f5257f1e807c2f197dcf5dcb2385cedca0ea
## Why
Older executors do not support resolving HTTP header values from their own
environment. Sending environment-backed bearer tokens to them can prevent MCP
servers from starting.
## What changed
- Advertise executor support for environment-backed HTTP headers with the
`httpHeaderEnvVars` capability.
- Delegate bearer-token resolution only when the selected executor advertises
that capability; otherwise, resolve tokens available in the host environment.
- Exclude executor-owned MCP servers that require environment-backed bearer
tokens when the executor cannot resolve them, while retaining compatible
host-owned and executor-owned servers.
## Testing
Added protocol and environment-variable coverage plus an end-to-end test that
simulates an older executor and verifies compatible MCP servers remain usable.
GitOrigin-RevId: 43545926f6f7e0f3b1091eb29d34647f6372bc4a
## What changed
- Read `mcp_servers` configuration and requirements from each selected remote
executor and add eligible HTTP servers to the thread's MCP runtime.
- Bind discovered servers to the thread's concrete executor snapshot and apply
environment MCP policy and requirements. Discovery is best effort, and
executor-local servers are not treated as required at startup.
- Ignore unsupported stdio servers and HTTP configurations that depend on
environment-provided headers or header helpers.
## Testing
- Added an app-server integration test covering discovery, authenticated HTTP
tool invocation, requirements enforcement, and exclusion of stdio servers.
GitOrigin-RevId: 6e1cdcebdbb1cc21a5a2285fbc5617d8d5997182
## What changed
- Add the `environmentConfig/read` RPC for selecting literal TOML paths from executor-local config and requirements layers.
- Return layer precedence, cloud insertion points, source and base-directory metadata, and executor home and hostname context without normalizing path-bearing values.
- Expose the operation through both remote clients and local `Environment` instances, with invalid selectors reported as invalid parameters.
## Testing
- Cover projected remote config reads and rejection of empty selectors.
GitOrigin-RevId: fee15bf833de6bcb2058d405ed5b1d5d928d7218
zm-oai