## Why
Fixes#18475. A `-c` override such as `projects.<cwd>.trust_level =
"untrusted"` is meant to be a runtime config override, but app-server
thread startup treated any non-trusted project as eligible for automatic
trust persistence when a permissive sandbox/cwd was requested. That
meant an explicit `untrusted` session override could still cause
`config.toml` to be updated with `trusted`.
## What changed
The app-server auto-trust path now runs only when the active project
trust level is unknown. Explicit `trusted` and explicit `untrusted`
values are both respected, regardless of whether they came from
persisted config or session flags.
A focused `thread/start` test now covers the explicit `untrusted` case
with a permissive sandbox request.
## Verification
- `cargo test -p codex-app-server`
- `just fix -p codex-app-server`
Eric TrautandGitHub
c2423f42d1