app-server: use profile ids in v2 permission params (#23360)

## Why

The v2 app-server permission profile fields are experimental, but the
previous migration kept a legacy object payload for profile selection.
That made clients aware of server-owned `activePermissionProfile`
metadata such as `extends`, and it kept a
`legacy_additional_writable_roots` path even though
`runtimeWorkspaceRoots` now owns runtime workspace-root selection.

This PR makes the client contract match the intended model: clients
select a permission profile by id, and the server resolves and reports
active profile provenance in response payloads.

Follow-up to #22611.

## What Changed

- Changed `thread/start`, `thread/resume`, `thread/fork`, and
`turn/start` permission profile selection to plain profile id strings.
- Changed `command/exec.permissionProfile` to a plain profile id string
for the same client/server ownership split.
- Removed `PermissionProfileSelectionParams` and the legacy `{ type:
"profile", modifications: [...] }` compatibility deserializer.
- Updated app-server, TUI, and `codex exec` call sites to send only ids,
while keeping `activePermissionProfile` as server response metadata.
- Updated app-server docs and schema fixtures for the revised
`command/exec.permissionProfile` shape.

## Verification

- `cargo test -p codex-app-server-protocol`
- `RUST_MIN_STACK=8388608 cargo test -p codex-app-server`
- `cargo test -p codex-exec`
- `RUST_MIN_STACK=8388608 cargo test -p codex-tui`

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/23360).
* #23368
* __->__ #23360

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

@@ -117,13 +117,6 @@ impl CommandExecRequestProcessor {
                 "`permissionProfile` cannot be combined with `sandboxPolicy`",
             ));
         }
-        let permission_profile = if let Some(active_permission_profile) = permission_profile {
-            Some(PermissionProfileSelectionParams::new(
-                active_permission_profile.id,
-            ))
-        } else {
-            None
-        };
 
         if size.is_some() && !tty {
             return Err(invalid_params("command/exec size requires tty: true"));
@@ -199,14 +192,11 @@ impl CommandExecRequestProcessor {
             network_proxy_permission_profile,
             managed_network_requirements_enabled,
         ) = if let Some(permission_profile) = permission_profile {
-            let mut overrides = ConfigOverrides {
+            let overrides = ConfigOverrides {
                 cwd: Some(cwd.to_path_buf()),
+                default_permissions: Some(permission_profile),
                 ..Default::default()
             };
-            apply_permission_profile_selection_to_config_overrides(
-                &mut overrides,
-                Some(permission_profile),
-            );
             let config = self
                 .config_manager
                 .load_for_cwd(

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

@@ -1239,17 +1239,18 @@ impl ThreadRequestProcessor {
         approval_policy: Option<codex_app_server_protocol::AskForApproval>,
         approvals_reviewer: Option<codex_app_server_protocol::ApprovalsReviewer>,
         sandbox: Option<SandboxMode>,
-        permissions: Option<PermissionProfileSelectionParams>,
+        permissions: Option<String>,
         base_instructions: Option<String>,
         developer_instructions: Option<String>,
         personality: Option<Personality>,
     ) -> ConfigOverrides {
-        let mut overrides = ConfigOverrides {
+        ConfigOverrides {
             model,
             model_provider,
             service_tier,
             cwd: cwd.map(PathBuf::from),
             workspace_roots: runtime_workspace_roots,
+            default_permissions: permissions,
             approval_policy: approval_policy
                 .map(codex_app_server_protocol::AskForApproval::to_core),
             approvals_reviewer: approvals_reviewer
@@ -1261,9 +1262,7 @@ impl ThreadRequestProcessor {
             developer_instructions,
             personality,
             ..Default::default()
-        };
-        apply_permission_profile_selection_to_config_overrides(&mut overrides, permissions);
-        overrides
+        }
     }
 
     fn parse_environment_selections(

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

@@ -175,29 +175,6 @@ pub(super) fn thread_response_active_permission_profile(
     active_permission_profile.map(Into::into)
 }
 
-pub(super) fn apply_permission_profile_selection_to_config_overrides(
-    overrides: &mut ConfigOverrides,
-    permissions: Option<PermissionProfileSelectionParams>,
-) {
-    let Some(selection) = permissions else {
-        return;
-    };
-    overrides.default_permissions = Some(selection.id().to_string());
-    if selection.legacy_additional_writable_roots().is_empty() {
-        return;
-    }
-
-    let legacy_roots = selection
-        .legacy_additional_writable_roots()
-        .iter()
-        .map(AbsolutePathBuf::to_path_buf);
-    if let Some(workspace_roots) = overrides.workspace_roots.as_mut() {
-        workspace_roots.extend(legacy_roots);
-    } else {
-        overrides.additional_writable_roots.extend(legacy_roots);
-    }
-}
-
 pub(super) fn thread_response_sandbox_policy(
     permission_profile: &codex_protocol::models::PermissionProfile,
     cwd: &Path,

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

@@ -66,43 +66,3 @@ fn extract_conversation_summary_prefers_plain_user_messages() -> Result<()> {
     assert_eq!(summary, expected);
     Ok(())
 }
-
-#[test]
-fn legacy_permission_profile_modifications_extend_runtime_roots() -> Result<()> {
-    let root = if cfg!(windows) {
-        AbsolutePathBuf::try_from("C:\\workspace-extra")?
-    } else {
-        AbsolutePathBuf::try_from("/workspace-extra")?
-    };
-    let selection = serde_json::from_value::<PermissionProfileSelectionParams>(json!({
-        "type": "profile",
-        "id": ":workspace",
-        "modifications": [
-            {
-                "type": "additionalWritableRoot",
-                "path": root,
-            }
-        ],
-    }))?;
-
-    let mut overrides = ConfigOverrides::default();
-    apply_permission_profile_selection_to_config_overrides(&mut overrides, Some(selection.clone()));
-    assert_eq!(
-        overrides.default_permissions,
-        Some(":workspace".to_string())
-    );
-    assert_eq!(
-        overrides.additional_writable_roots,
-        vec![root.to_path_buf()]
-    );
-
-    let mut overrides = ConfigOverrides {
-        workspace_roots: Some(Vec::new()),
-        ..ConfigOverrides::default()
-    };
-    apply_permission_profile_selection_to_config_overrides(&mut overrides, Some(selection));
-    assert_eq!(overrides.additional_writable_roots, Vec::<PathBuf>::new());
-    assert_eq!(overrides.workspace_roots, Some(vec![root.to_path_buf()]));
-
-    Ok(())
-}

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

@@ -425,7 +425,7 @@ impl TurnRequestProcessor {
                         "turn/start permission selection missing thread snapshot",
                     ));
                 };
-                let mut overrides = ConfigOverrides {
+                let overrides = ConfigOverrides {
                     cwd: cwd.clone(),
                     workspace_roots: Some(runtime_workspace_roots_request.clone().unwrap_or_else(
                         || {
@@ -436,14 +436,11 @@ impl TurnRequestProcessor {
                                 .collect()
                         },
                     )),
+                    default_permissions: Some(permissions),
                     codex_linux_sandbox_exe: self.arg0_paths.codex_linux_sandbox_exe.clone(),
                     main_execve_wrapper_exe: self.arg0_paths.main_execve_wrapper_exe.clone(),
                     ..Default::default()
                 };
-                apply_permission_profile_selection_to_config_overrides(
-                    &mut overrides,
-                    Some(permissions),
-                );
                 let config = self
                     .config_manager
                     .load_for_cwd(