## What changed
Negotiate executor support for `credential_masking` and enable built-in credential brokerage in executor-local network proxies. Supported non-login Bash commands on Linux and macOS receive credential placeholders, with real credentials injected by the proxy for matching destinations.
Retain credential mappings across process launches within the same executor session, scoped by environment, conversation, and broker configuration. Keep credentials and destination context on the executor.
Fall back to unmasked execution for unsupported shells or shell startup, and for configured credential providers. Emit warnings when masking is unavailable, preserving shell profiles and snapshots.
## Testing
Add coverage for capability negotiation, fallback behavior, mapping reuse and isolation, proxy credential injection, and keeping executor credentials out of model-visible request history. Test warning, removal, and rejection modes for credentials left unmasked during preparation.
GitOrigin-RevId: f64e916a5de8350fa0d289d3440ec29761accd75
## What changed
Move `ExecServerProcess` into `core_test_support::exec_server` and update the sandbox, plugin, access, and turn-input tests to use it. Preserve the fixture's startup timeout, temporary `CODEX_HOME`, WebSocket URL discovery, and child-process cleanup.
GitOrigin-RevId: 152de3a83f4ad39e2c1223e15438608dba452850