app-server: stop returning thread permission profiles (#22792)

## Why

The app-server thread lifecycle API should no longer expose the full
`PermissionProfile` value. After the permissions-profile migration,
clients should round-trip only the active profile identity through
`activePermissionProfile` and `permissions` when that identity is known.

The full profile is server-side config. Treating a response-derived
legacy sandbox projection as a new local profile can lose named-profile
restrictions and accidentally widen permissions on the next turn. The
legacy `sandbox` response field remains only as the
compatibility/display fallback.

## What Changed

- Removed `permissionProfile` from `ThreadStartResponse`,
`ThreadResumeResponse`, and `ThreadForkResponse`.
- Stopped populating that field in app-server thread start/resume/fork
responses.
- Updated embedded exec/TUI response mapping to derive display
permission state from local config or the legacy sandbox fallback
instead of a response profile value.
- Added a TUI turn override shape that distinguishes preserving server
permissions, selecting an active profile id, and sending a legacy
sandbox for an explicit local override.
- Preserved remote app-server permissions across turns by sending
`permissions` only when an `activePermissionProfile` id is known, and
otherwise sending no sandbox override unless the user selected a local
override.
- Kept embedded `thread/resume` hydration server-authored when
`activePermissionProfile` is absent, which matches the live-thread
attach path where the server ignores requested overrides.
- Updated the app-server README to remove the obsolete lifecycle
response `permissionProfile` reference. The remaining
`permissionProfile` README references are request-side permission
overrides.
- Regenerated app-server JSON schema and TypeScript fixtures.
- Kept the generated typed response enum exempt from
`large_enum_variant`, matching the existing payload enum exemption after
the lifecycle response variants shrank.

## How To Review

Start with `codex-rs/app-server-protocol/src/protocol/v2/thread.rs` to
confirm the response shape, then check the response construction in
`codex-rs/app-server/src/request_processors`. The generated schema and
TypeScript fixture changes are mechanical follow-through from the
protocol removal.

The TUI behavior is the delicate part: review
`codex-rs/tui/src/app_server_session.rs` for response hydration and
turn-start override projection, then
`codex-rs/tui/src/app/thread_routing.rs` for the decision about whether
the next turn should preserve the server snapshot, send an active
profile id, or send a legacy sandbox for an explicit local override.

## Verification

- `just write-app-server-schema`
- `cargo test -p codex-app-server-protocol
thread_lifecycle_responses_default_missing_optional_fields`
- `cargo test -p codex-exec
session_configured_from_thread_response_uses_permission_profile_from_config`
- `cargo test -p codex-tui --lib thread_response`
- `cargo test -p codex-tui turn_permissions_`
- `cargo test -p codex-tui
resume_response_restores_turns_from_thread_items`
- `cargo test -p codex-analytics
track_response_only_enqueues_analytics_relevant_responses`
- `just fix -p codex-analytics`
- `just fix -p codex-app-server-protocol`
- `just fix -p codex-tui`
- `just argument-comment-lint`

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/22792).
* #22795
* __->__ #22792

codex-rs/app-server/README.md

@@ -133,7 +133,7 @@ Example with notification opt-out:
 - `thread/start` — create a new thread; emits `thread/started` (including the current `thread.status`) and auto-subscribes you to turn/item events for that thread. When the request includes a `cwd` and the resolved sandbox is `workspace-write` or full access, app-server also marks that project as trusted in the user `config.toml`. Pass `sessionStartSource: "clear"` when starting a replacement thread after clearing the current session so `SessionStart` hooks receive `source: "clear"` instead of the default `"startup"`. Experimental `runtimeWorkspaceRoots` replaces the thread-scoped runtime workspace roots used to materialize `:workspace_roots`; relative paths resolve against the effective thread cwd. For permissions, prefer experimental `permissions` profile selection by id; the legacy `sandbox` shorthand is still accepted but cannot be combined with `permissions`. Experimental `environments` selects the sticky execution environments for turns on the thread; omit it to use the server default, pass `[]` to disable environments, or pass explicit environment ids with per-environment `cwd`.
 - `thread/resume` — reopen an existing thread by id so subsequent `turn/start` calls append to it. Accepts the same permission override rules as `thread/start`.
 - `thread/fork` — fork an existing thread into a new thread id by copying the stored history; if the source thread is currently mid-turn, the fork records the same interruption marker as `turn/interrupt` instead of inheriting an unmarked partial turn suffix. The returned `thread.forkedFromId` points at the source thread when known. Accepts `ephemeral: true` for an in-memory temporary fork, emits `thread/started` (including the current `thread.status`), and auto-subscribes you to turn/item events for the new thread. Experimental clients can pass `excludeTurns: true` when they plan to page fork history via `thread/turns/list` instead of receiving the full turn array immediately. Accepts the same permission override rules as `thread/start`.
-- `thread/start`, `thread/resume`, and `thread/fork` responses include the legacy `sandbox` compatibility projection. Experimental clients can read `runtimeWorkspaceRoots` for the thread-scoped runtime roots, `permissionProfile` for the exact active runtime permissions, and `activePermissionProfile` for the named or implicit built-in profile identity/provenance when known.
+- `thread/start`, `thread/resume`, and `thread/fork` responses include the legacy `sandbox` compatibility projection. Experimental clients can read `runtimeWorkspaceRoots` for the thread-scoped runtime roots and `activePermissionProfile` for the named or implicit built-in profile identity/provenance when known.
 - `thread/list` — page through stored rollouts; supports cursor-based pagination and optional `modelProviders`, `sourceKinds`, `archived`, `cwd`, and `searchTerm` filters. Each returned `thread` includes `status` (`ThreadStatus`), defaulting to `notLoaded` when the thread is not currently loaded.
 - `thread/loaded/list` — list the thread ids currently loaded in memory.
 - `thread/read` — read a stored thread by id without resuming it; optionally include turns via `includeTurns`. The returned `thread` includes `status` (`ThreadStatus`), defaulting to `notLoaded` when the thread is not currently loaded.

codex-rs/app-server/src/request_processors/thread_lifecycle.rs

@@ -626,7 +626,6 @@ pub(super) async fn handle_pending_thread_resume_request(
         approval_policy: approval_policy.into(),
         approvals_reviewer: approvals_reviewer.into(),
         sandbox,
-        permission_profile: Some(permission_profile.into()),
         active_permission_profile,
         reasoning_effort,
     };

codex-rs/app-server/src/request_processors/thread_processor.rs

@@ -1199,7 +1199,6 @@ impl ThreadRequestProcessor {
             approval_policy: config_snapshot.approval_policy.into(),
             approvals_reviewer: config_snapshot.approvals_reviewer.into(),
             sandbox,
-            permission_profile: Some(config_snapshot.permission_profile.into()),
             active_permission_profile,
             reasoning_effort: config_snapshot.reasoning_effort,
         };
@@ -2554,7 +2553,6 @@ impl ThreadRequestProcessor {
                     approval_policy: session_configured.approval_policy.into(),
                     approvals_reviewer: session_configured.approvals_reviewer.into(),
                     sandbox,
-                    permission_profile: Some(config_snapshot.permission_profile.into()),
                     active_permission_profile,
                     reasoning_effort: session_configured.reasoning_effort,
                 };
@@ -3215,7 +3213,6 @@ impl ThreadRequestProcessor {
             approval_policy: session_configured.approval_policy.into(),
             approvals_reviewer: session_configured.approvals_reviewer.into(),
             sandbox,
-            permission_profile: Some(config_snapshot.permission_profile.into()),
             active_permission_profile,
             reasoning_effort: session_configured.reasoning_effort,
         };