## Why
This PR builds on [#22610](https://github.com/openai/codex/pull/22610)
and is the app-server side of the migration from mutable per-turn
`SandboxPolicy` replacement toward selecting immutable permission
profiles by id plus mutable runtime workspace roots.
Once permission profiles can carry their own immutable
`workspace_roots`, app-server no longer needs to mutate the selected
`PermissionProfile` just to represent thread-specific filesystem
context. The mutable part now lives on the thread as explicit
`runtimeWorkspaceRoots`, while `:workspace_roots` remains symbolic until
the sandbox is realized for a turn.
## What Changed
- Replaced the v2 permission-selection wrapper surface with plain
profile ids for `thread/start`, `thread/resume`, `thread/fork`, and
`turn/start`.
- Removed the API surface for profile modifications
(`PermissionProfileSelectionParams`,
`PermissionProfileModificationParams`,
`ActivePermissionProfileModification`).
- Added experimental `runtimeWorkspaceRoots` fields to the thread
lifecycle and turn-start APIs.
- Threaded runtime workspace roots through core session/thread
snapshots, turn overrides, app-server request handling, and command
execution permission resolution.
- Kept session permission state symbolic so later runtime root updates
and cwd-only implicit-root retargeting rebind `:workspace_roots`
correctly.
- Updated the embedded clients just enough to send and restore the new
thread state.
- Refreshed the generated schema/TypeScript artifacts and the app-server
README to match the new contract.
## Verification
Targeted coverage for this layer lives in:
- `codex-rs/app-server-protocol/src/protocol/v2/tests.rs`
- `codex-rs/app-server/tests/suite/v2/thread_start.rs`
- `codex-rs/app-server/tests/suite/v2/thread_resume.rs`
- `codex-rs/app-server/tests/suite/v2/turn_start.rs`
- `codex-rs/core/src/session/tests.rs`
The key regression checks exercise that:
- `runtimeWorkspaceRoots` resolve against the effective cwd on thread
start.
- Profile-declared workspace roots are excluded from the runtime
workspace roots returned by app-server.
- A turn-level runtime workspace-root update persists onto the thread
and is returned by `thread/resume`.
- A named permission profile selected on one turn remains symbolic so a
later runtime-root-only turn update changes the actual sandbox writes.
- A cwd-only turn update retargets the implicit runtime cwd root while
preserving additional runtime roots.
- The protocol fixtures and generated client artifacts stay in sync with
the string-based permission selection contract.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/22611).
* #22612
* __->__ #22611
## Why
This is the configuration/model half of the alternative permissions
migration we discussed as a comparison point for
[#22401](https://github.com/openai/codex/pull/22401) and
[#22402](https://github.com/openai/codex/pull/22402).
The old `workspace-write` model mixes three concerns that we want to
keep separate:
- reusable profile rules that should stay immutable once selected
- user/runtime workspace roots from `cwd`, `--add-dir`, and legacy
workspace-write config
- internal Codex writable roots such as memories, which should not be
shown as user workspace roots
This PR gives permission profiles first-class `workspace_roots` so users
can opt multiple repositories into the same `:workspace_roots` rules
without using broad absolute-path write grants. It also starts
separating the raw selected profile from the effective runtime profile
by making `Permissions` expose explicit accessors instead of public
mutable fields.
A representative `config.toml` looks like this:
```toml
default_permissions = "dev"
[permissions.dev.workspace_roots]
"~/code/openai" = true
"~/code/developers-website" = true
[permissions.dev.filesystem.":workspace_roots"]
"." = "write"
".codex" = "read"
".git" = "read"
".vscode" = "read"
```
If Codex starts in `~/code/codex` with that profile selected, the
effective workspace-root set becomes:
- `~/code/codex` from the runtime `cwd`
- `~/code/openai` from the profile
- `~/code/developers-website` from the profile
The `:workspace_roots` rules are materialized across each root, so
`.git`, `.codex`, and `.vscode` stay scoped the same way everywhere.
Runtime additions such as `--add-dir` can still layer on later stack
entries without mutating the selected profile.
## Stack Shape
This PR intentionally stops before the profile-identity cleanup in
[#22683](https://github.com/openai/codex/pull/22683) so the base review
stays focused on config loading, workspace-root materialization, and
compatibility with legacy `workspace-write`.
The representation in this PR is therefore transitional: `Permissions`
carries enough state to distinguish the raw constrained profile from the
effective runtime profile, and there are still call sites that must keep
the active profile identity and constrained profile value in sync. The
follow-up PR replaces that with a single resolved profile state
(`ResolvedPermissionProfile` / `PermissionProfileState`) that keeps the
profile id, immutable `PermissionProfile`, and profile-declared
workspace roots together. That follow-up removes APIs such as
`set_constrained_permission_profile_with_active_profile()` where
separate arguments could drift out of sync.
Downstream PRs then build on this base to switch app-server turn updates
to profile ids plus runtime workspace roots and to finish the
user-visible summary behavior. Reviewers should judge this PR as the
workspace-roots foundation, not as the final in-memory shape of selected
permission profiles.
## Review Guide
Suggested review order:
1. Start with `codex-rs/core/src/config/mod.rs`.
This is the main shape change in the base slice. `Permissions` now
stores a private raw `Constrained<PermissionProfile>` plus runtime
`workspace_roots`. Callers use `permission_profile()` when they need the
raw constrained value and `effective_permission_profile()` when they
need a materialized runtime profile. As noted above,
[#22683](https://github.com/openai/codex/pull/22683) replaces this
transitional shape with a resolved profile state that keeps identity and
profile data together.
2. Review `codex-rs/config/src/permissions_toml.rs` and
`codex-rs/core/src/config/permissions.rs`.
These add `[permissions.<id>.workspace_roots]`, resolve enabled entries
relative to the policy cwd, and keep `:workspace_roots` deny-read glob
patterns symbolic until the actual roots are known.
3. Review `codex-rs/protocol/src/permissions.rs` and
`codex-rs/protocol/src/models.rs`.
These add the policy/profile materialization helpers that expand exact
`:workspace_roots` entries and scoped deny-read globs over every
workspace root. This is also where `ActivePermissionProfileModification`
is removed from the core model.
4. Review the legacy bridge in
`Config::load_from_base_config_with_overrides` and
`Config::set_legacy_sandbox_policy`.
This is where legacy `workspace-write` roots become runtime workspace
roots, while Codex internal writable roots stay internal and do not
appear as user-facing workspace roots.
5. Then skim downstream call sites.
The interesting pattern is raw-vs-effective access: state/proxy/bwrap
paths keep the raw constrained profile, while execution, summaries, and
user-visible status use the effective profile and workspace-root list.
## What Changed
- added `[permissions.<id>.workspace_roots]` to the config model and
schema
- added runtime `workspace_roots` state to `Config`/`Permissions` and
`ConfigOverrides`
- made `Permissions` profile fields private and replaced direct mutation
with accessors/setters
- added `PermissionProfile` and `FileSystemSandboxPolicy` helpers for
materializing `:workspace_roots` exact paths and deny-read globs across
all roots
- moved legacy additional writable roots into runtime workspace-root
state instead of active profile modifications
- removed `ActivePermissionProfileModification` and its app-server
protocol/schema export
- updated sandbox/status summary paths so internal writable roots are
not reported as user workspace roots
## Verification Strategy
The targeted tests cover the behavior at the layers where regressions
are most likely:
- `codex-rs/core/src/config/config_tests.rs` verifies config loading,
legacy workspace-root seeding, effective profile materialization, and
memory-root handling.
- `codex-rs/core/src/config/permissions_tests.rs` verifies profile
`workspace_roots` parsing and `:workspace_roots` scoped/glob
compilation.
- `codex-rs/protocol/src/permissions.rs` unit tests verify exact and
glob materialization over multiple workspace roots.
- `codex-rs/tui/src/status/tests.rs` and
`codex-rs/utils/sandbox-summary/src/sandbox_summary.rs` verify the
user-facing summaries show effective workspace roots and hide internal
writes.
I also ran `cargo check --tests` locally after the latest stack refresh
to catch cross-crate API breakage from the private-field/accessor
changes.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/22610).
* #22612
* #22611
* #22683
* __->__ #22610
## Why
`thread_start_params_include_review_policy_when_review_policy_is_manual_only`
builds a `Config` with a temporary `CODEX_HOME`, but
`ConfigBuilder::default()` can still load host-managed configuration. On
local macOS machines with enterprise-managed Codex config, that host
state can leak into the test and change the resulting config, even
though CI does not have the same managed config source.
This makes the test environment-dependent: it can pass in CI while
failing locally for developers who have managed configuration installed.
## What Changed
- Updated `codex-rs/exec/src/lib_tests.rs` so the test calls
`LoaderOverrides::without_managed_config_for_tests()` through
`ConfigBuilder::loader_overrides(...)`.
- Left the rest of the test setup intact, including the temporary
`CODEX_HOME`, temporary cwd, and explicit `approvals_reviewer` harness
override.
## Verification
```shell
cargo test -p codex-exec thread_start_params_include_review_policy_when_review_policy_is_manual_only
```
`codex exec` should not print OpenTelemetry exporter self-diagnostics to
stderr by default. Suppress the SDK and OTLP exporter targets unless
callers
explicitly opt in with `RUST_LOG`.
Also stop defaulting the trace exporter to the log exporter, since OTLP
HTTP
endpoints are signal-specific and a logs endpoint is not valid for
spans.
Co-authored-by: Codex <noreply@openai.com>
Co-authored-by: Codex <noreply@openai.com>
## Why
`session_id` and `thread_id` are separate identities after #20437, but
app-server only surfaced `sessionId` on the `thread/start`,
`thread/resume`, and `thread/fork` response envelopes. Other
thread-bearing surfaces such as `thread/list`, `thread/read`,
`thread/started`, `thread/rollback`, `thread/metadata/update`, and
`thread/unarchive` either lacked the grouping key or forced clients to
special-case those three responses.
Making `sessionId` part of the reusable `Thread` payload gives every v2
API surface one place to expose session-tree identity.
## Mental model
1. thread.sessionId lives on `Thread`
2. It is a view/runtime identity for the current live session tree, not
durable stored lineage metadata
3. When app-server has a live loaded thread, it copies the real value
from core’s session_configured.session_id
4. When it only has stored/unloaded data, it falls back to
thread.sessionId = thread.id
## What changed
- Added `sessionId` to the v2
[`Thread`](8fc9e9b4cf/codex-rs/app-server-protocol/src/protocol/v2/thread_data.rs (L105-L109)).
- Removed the duplicate top-level `sessionId` fields from
`thread/start`, `thread/resume`, and `thread/fork`; clients should now
read `response.thread.sessionId`.
- Populated `thread.sessionId` when building live thread responses,
replaying loaded threads, and returning stored-thread summaries so the
field is present across start, resume, fork, list, read, rollback,
metadata-update, unarchive, and `thread/started` paths. See
[`load_thread_from_resume_source_or_send_internal`](8fc9e9b4cf/codex-rs/app-server/src/request_processors/thread_processor.rs (L2824-L2918))
and
[`thread_from_stored_thread`](8fc9e9b4cf/codex-rs/app-server/src/request_processors/thread_processor.rs (L3671-L3719)).
- Preserved the stored-thread fallback: if a thread has not been loaded
into a live session tree yet, `thread.sessionId` falls back to
`thread.id`; once the thread is live again, the field reports the active
session tree root.
- Regenerated the JSON/TypeScript schemas and updated the app-server
README examples to show
[`thread.sessionId`](8fc9e9b4cf/codex-rs/app-server/README.md (L306-L310))
on the thread object.
## Summary
Related to
https://openai.slack.com/archives/C095U48JNL9/p1777537279707449
TLDR:
We update the meaning of session ids and thread ids:
* thread_id stays as now
* session_id become a shared id between every thread under a /root
thread (i.e. every sub-agent share the same session id)
This PR introduces an explicit `SessionId` and threads it through the
protocol/client boundary so `session_id` and `thread_id` can diverge
when they need to, while preserving compatibility for older serialized
`session_configured` events.
---------
Co-authored-by: Codex <noreply@openai.com>
## Summary
- make `thread_source` an explicit optional thread-level field on
`thread/start`, `thread/fork`, and returned thread payloads
- persist `thread_source` in rollout/session metadata so resumed live
threads retain the original value
- replace the old best-effort `session_source` -> `thread_source`
mapping with an explicit caller-supplied analytics classification
## Why
Before this change, analytics `thread_source` was populated by a
best-effort mapping from `session_source`. `session_source` describes
the runtime/client surface, not the actual thread-level origin, so that
projection was not accurate enough to distinguish cases such as `user`,
`subagent`, `memory_consolidation`, and future thread origins reliably.
Making `thread_source` explicit keeps one thread-level analytics field
while letting callers provide the real classification directly instead
of recovering it indirectly from `session_source`.
## Impact
For new analytics events, `thread_source` now reflects the explicit
thread-level classification supplied by the caller rather than an
inferred value derived from `session_source`. Existing protocol fields
remain optional; callers that omit `threadSource` now produce `null`
instead of a best-effort inferred value.
## Validation
- `just write-app-server-schema`
- `cargo test -p codex-analytics -p codex-core -p
codex-app-server-protocol --no-run`
- `cargo test -p codex-app-server-protocol
generated_ts_optional_nullable_fields_only_in_params`
- `cargo test -p codex-analytics
thread_initialized_event_serializes_expected_shape`
- `cargo test -p codex-core
resume_stopped_thread_from_rollout_preserves_thread_source`
## Why
`Turn.items` currently overloads an empty array to mean either that no
items exist or that the server intentionally did not load them for this
response. That ambiguity blocks future lazy-loading work where clients
need to distinguish unloaded, summary, and fully hydrated turn payloads.
## What changed
- add a new `TurnItemsView` enum with `notLoaded`, `summary`, and `full`
variants
- add required `itemsView` metadata to app-server `Turn` payloads
- mark reconstructed persisted history as `full` and live shell-style
turn payloads as `notLoaded`
- keep current `thread/turns/list` behavior unchanged and document that
it still returns `full` turns today
- regenerate the JSON and TypeScript protocol fixtures
## Verification
- `just write-app-server-schema`
- `cargo test -p codex-app-server-protocol`
- `cargo test -p codex-app-server thread_read_can_include_turns`
- `cargo test -p codex-app-server
thread_turns_list_can_page_backward_and_forward`
- `cargo test -p codex-app-server
thread_resume_rejects_history_when_thread_is_running`
- `just fix -p codex-app-server-protocol`
- `just fix -p codex-app-server`
- `just fmt`
## Why
`ReadOnlyAccess` was a transitional legacy shape on `SandboxPolicy`:
`FullAccess` meant the historical read-only/workspace-write modes could
read the full filesystem, while `Restricted` tried to carry partial
readable roots. The partial-read model now belongs in
`FileSystemSandboxPolicy` and `PermissionProfile`, so keeping it on
`SandboxPolicy` makes every legacy projection reintroduce lossy
read-root bookkeeping and creates unnecessary noise in the rest of the
permissions migration.
This PR makes the legacy policy model narrower and explicit:
`SandboxPolicy::ReadOnly` and `SandboxPolicy::WorkspaceWrite` represent
the old full-read sandbox modes only. Split readable roots, deny-read
globs, and platform-default/minimal read behavior stay in the runtime
permissions model.
## What changed
- Removes `ReadOnlyAccess` from
`codex_protocol::protocol::SandboxPolicy`, including the generated
`access` and `readOnlyAccess` API fields.
- Updates legacy policy/profile conversions so restricted filesystem
reads are represented only by `FileSystemSandboxPolicy` /
`PermissionProfile` entries.
- Keeps app-server v2 compatible with legacy `fullAccess` read-access
payloads by accepting and ignoring that no-op shape, while rejecting
legacy `restricted` read-access payloads instead of silently widening
them to full-read legacy policies.
- Carries Windows sandbox platform-default read behavior with an
explicit override flag instead of depending on
`ReadOnlyAccess::Restricted`.
- Refreshes generated app-server schema/types and updates tests/docs for
the simplified legacy policy shape.
## Verification
- `cargo check -p codex-app-server-protocol --tests`
- `cargo check -p codex-windows-sandbox --tests`
- `cargo test -p codex-app-server-protocol sandbox_policy_`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19449).
* #19395
* #19394
* #19393
* #19392
* #19391
* __->__ #19449
## Why
The profile conversion path still required a `cwd` even when it was only
translating a legacy `SandboxPolicy` into a `PermissionProfile`. That
made profile producers invent an ambient `cwd`, which is exactly the
anchoring we are trying to remove from permission-profile data. A legacy
workspace-write policy can be represented symbolically instead: `:cwd =
write` plus read-only `:project_roots` metadata subpaths.
This PR creates that cwd-free base so the rest of the stack can stop
threading cwd through profile construction. Callers that actually need a
concrete runtime filesystem policy for a specific cwd still have an
explicitly named cwd-bound conversion.
## What Changed
- `PermissionProfile::from_legacy_sandbox_policy` now takes only
`&SandboxPolicy`.
- `FileSystemSandboxPolicy::from_legacy_sandbox_policy` is now the
symbolic, cwd-free projection for profiles.
- The old concrete projection is retained as
`FileSystemSandboxPolicy::from_legacy_sandbox_policy_for_cwd` for
runtime/boundary code that must materialize legacy cwd behavior.
- Workspace-write profiles preserve `CurrentWorkingDirectory` and
`ProjectRoots` special entries instead of materializing cwd into
absolute paths.
## Verification
- `cargo check -p codex-protocol -p codex-core -p
codex-app-server-protocol -p codex-app-server -p codex-exec -p
codex-exec-server -p codex-tui -p codex-sandboxing -p
codex-linux-sandbox -p codex-analytics --tests`
- `just fix -p codex-protocol -p codex-core -p codex-app-server-protocol
-p codex-app-server -p codex-exec -p codex-exec-server -p codex-tui -p
codex-sandboxing -p codex-linux-sandbox -p codex-analytics`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/19414).
* #19395
* #19394
* #19393
* #19392
* #19391
* __->__ #19414
## Why
`approvals_reviewer` now uses `auto_review` as the canonical config/API
value after #18504, but the Rust enum variant and nearby helper/test
names still used `GuardianSubagent` / guardian approval wording. That
made follow-up code and reviews confusing even though the external value
had already moved to Auto-review.
## What changed
- Renamed `ApprovalsReviewer::GuardianSubagent` to
`ApprovalsReviewer::AutoReview`.
- Updated protocol, app-server, config, core, TUI, exec, and analytics
test callsites.
- Renamed nearby helper/test names from guardian approval wording to
Auto-review wording where they refer to the approvals reviewer mode.
- Preserved wire compatibility:
- `auto_review` remains the canonical serialized value.
- `guardian_subagent` remains accepted as a legacy alias.
This intentionally does not rename the `[features].guardian_approval`
key, `Feature::GuardianApproval`, `core/src/guardian`, analytics event
names, or app-server Guardian review event types.
## Verification
- `cargo test -p codex-protocol
approvals_reviewer_serializes_auto_review_and_accepts_legacy_guardian_subagent`
- `cargo test -p codex-app-server-protocol
approvals_reviewer_serializes_auto_review_and_accepts_legacy_guardian_subagent`
- `cargo test -p codex-config approvals_reviewer`
- `cargo test -p codex-tui update_feature_flags`
- `cargo test -p codex-core permissions_instructions`
- `cargo test -p codex-tui permissions_selection`
## Why
After app-server can accept `PermissionProfile`, first-party clients
should stop preferring legacy sandbox fields when canonical permission
information is available. This keeps the migration moving without
removing legacy compatibility yet.
The client side still has mixed surfaces during the stack: embedded
thread start/resume/fork and exec initial turns can derive a profile
directly from local config, while TUI remote sessions and some
turn-start paths only have a legacy/server-context-safe sandbox
projection. Those paths keep sending legacy sandbox fields rather than
synthesizing or sending lossy/local-only profiles.
## What changed
- Sends `permissionProfile` from exec and embedded TUI thread
start/resume/fork requests when config has a representable profile.
- Keeps legacy sandbox fallback for external sandbox policies, TUI
remote thread lifecycle requests, and TUI turn-start requests that do
not yet carry the active profile.
- Sends the actual config-derived `permissionProfile` for exec initial
turns instead of rebuilding one from the legacy sandbox projection.
- Stores response `permissionProfile` as optional in TUI session state
so external sandbox responses and compatibility payloads preserve
`null`.
- Updates tests for request construction and response mapping.
## Verification
- `cargo check --tests -p codex-tui -p codex-exec`
- `cargo test -p codex-tui app_server_session -- --nocapture`
- `cargo test -p codex-exec thread_start_params -- --nocapture`
- `cargo test -p codex-tui
app_server_session::tests::thread_lifecycle_params -- --nocapture`
- `just fix -p codex-tui -p codex-exec`
- `just fix -p codex-tui`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/18280).
* #18288
* #18287
* #18286
* #18285
* #18284
* #18283
* #18282
* #18281
* __->__ #18280
## Why
The `PermissionProfile` migration needs app-server clients to see the
same constrained permission model that core is using at runtime. Before
this PR, thread lifecycle responses only exposed the legacy
`SandboxPolicy` shape, so clients still had to infer active permissions
from sandbox fields. That makes downstream resume, fork, and override
flows harder to make `PermissionProfile`-first.
External sandbox policies are intentionally excluded from this canonical
view. External enforcement cannot be round-tripped as a
`PermissionProfile`, and exposing a lossy root-write profile would let
clients accidentally change sandbox semantics if they echo the profile
back later.
## What changed
- Adds the app-server v2 `PermissionProfile` wire shape, including
filesystem permissions and glob scan depth metadata.
- Adds `PermissionProfileNetworkPermissions` so the profile response
does not expose active network state through the older
additional-permissions naming.
- Returns `permissionProfile` from thread start, resume, and fork
responses when the active sandbox can be represented as a
`PermissionProfile`.
- Keeps legacy `sandbox` in those responses for compatibility and
documents `permissionProfile` as canonical when present.
- Makes lifecycle `permissionProfile` nullable and returns `null` for
`ExternalSandbox` to avoid exposing a lossy profile.
- Regenerates the app-server JSON schema and TypeScript fixtures.
## Verification
- `cargo test -p codex-app-server-protocol`
- `cargo test -p codex-app-server
thread_response_permission_profile_omits_external_sandbox --
--nocapture`
- `cargo check --tests -p codex-analytics -p codex-exec -p codex-tui`
- `just fix -p codex-app-server-protocol -p codex-app-server -p
codex-analytics -p codex-exec -p codex-tui`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/18278).
* #18279
* __->__ #18278
Addresses #17498
Problem: The TUI derived /status instruction source paths from the local
client environment, which could show stale <none> output or incorrect
paths when connected to a remote app server.
Solution: Add an app-server v2 instructionSources snapshot to thread
start/resume/fork responses, default it to an empty list when older
servers omit it, and render TUI /status from that server-provided
session data.
Additional context: The app-server field is intentionally named
instructionSources rather than AGENTS.md-specific terminology because
the loaded instruction sources can include global instructions, project
AGENTS.md files, AGENTS.override.md, user-defined instruction files, and
future dynamic sources.
Addresses #16781
Problem: `codex exec --ephemeral` backfilled empty `turn/completed`
items with `thread/read(includeTurns=true)`, which app-server rejects
for ephemeral threads.
This is a regression introduced in the recent conversion of "exec" to
use app server rather than call the core directly.
Solution: Skip turn-item backfill for ephemeral exec threads while
preserving the existing recovery path for non-ephemeral sessions.
Addresses #16560
Problem: `/status` stopped showing the source thread id in forked TUI
sessions after the app-server migration.
Solution: Carry fork source ids through app-server v2 thread data and
the TUI session adapter, and update TUI fixtures so `/status` matches
the old TUI behavior.
## Why
`codex-rs/exec/src/lib.rs` already keeps unit tests in a sibling
`lib_tests.rs` module so the implementation stays top-heavy and easier
to read. This applies that same layout to the rest of
`codex-rs/exec/src` so each production file keeps its entry points and
helpers ahead of test code.
## What
- Move inline unit tests out of `cli.rs`, `main.rs`,
`event_processor_with_human_output.rs`, and
`event_processor_with_jsonl_output.rs` into sibling `*_tests.rs` files.
- Keep test modules wired through `#[cfg(test)]` plus `#[path = "..."]
mod tests;`, matching the `lib.rs` pattern.
- Preserve the existing test coverage and assertions while making this a
source-layout-only refactor.
## Verification
- `cargo test -p codex-exec`
