app-server: drop legacy profile config surface (#24067)

## Why

Legacy `[profiles.<name>]` config tables and the legacy `profile`
selector are being retired in favor of profile files selected with
`--profile <name>`. After #23886 removed the CLI-side legacy profile
plumbing, the app-server config surface still exposed those fields and
still carried conversion code for the old protocol shape.

## What changed

- Remove `profile`, `profiles`, and `ProfileV2` from the app-server
config protocol/schema output so `config/read` no longer returns legacy
profile config.
- Drop the old v1 `UserSavedConfig` profile conversion path from
`config`.
- Reject new app-server config writes under `profiles.*` with the same
migration direction used for `profile`, while still allowing callers to
clear existing legacy profile tables.
- Refresh app-server config coverage and the experimental API README
example around the remaining `Config` nesting path.

## Verification

- Added config-manager coverage that `config/read` omits legacy profile
config, `profiles.*` writes are rejected, and existing legacy profile
tables can still be cleared.
- Updated the v2 config RPC test to cover the rejected `profiles.*`
batch-write path.

codex-rs/app-server-protocol/src/protocol/v2/tests.rs

@@ -1505,32 +1505,6 @@ fn ask_for_approval_granular_is_marked_experimental() {
     );
 }
 
-#[test]
-fn profile_v2_granular_approval_policy_is_marked_experimental() {
-    let reason = crate::experimental_api::ExperimentalApi::experimental_reason(&ProfileV2 {
-        model: None,
-        model_provider: None,
-        approval_policy: Some(AskForApproval::Granular {
-            sandbox_approval: true,
-            rules: false,
-            skill_approval: false,
-            request_permissions: true,
-            mcp_elicitations: false,
-        }),
-        approvals_reviewer: None,
-        service_tier: None,
-        model_reasoning_effort: None,
-        model_reasoning_summary: None,
-        model_verbosity: None,
-        web_search: None,
-        tools: None,
-        chatgpt_base_url: None,
-        additional: HashMap::new(),
-    });
-
-    assert_eq!(reason, Some("askForApproval.granular"));
-}
-
 #[test]
 fn config_granular_approval_policy_is_marked_experimental() {
     let reason = crate::experimental_api::ExperimentalApi::experimental_reason(&Config {
@@ -1554,8 +1528,6 @@ fn config_granular_approval_policy_is_marked_experimental() {
         forced_login_method: None,
         web_search: None,
         tools: None,
-        profile: None,
-        profiles: HashMap::new(),
         instructions: None,
         developer_instructions: None,
         compact_prompt: None,
@@ -1589,116 +1561,6 @@ fn config_approvals_reviewer_is_marked_experimental() {
         forced_login_method: None,
         web_search: None,
         tools: None,
-        profile: None,
-        profiles: HashMap::new(),
-        instructions: None,
-        developer_instructions: None,
-        compact_prompt: None,
-        model_reasoning_effort: None,
-        model_reasoning_summary: None,
-        model_verbosity: None,
-        service_tier: None,
-        analytics: None,
-        apps: None,
-        desktop: None,
-        additional: HashMap::new(),
-    });
-
-    assert_eq!(reason, Some("config/read.approvalsReviewer"));
-}
-
-#[test]
-fn config_nested_profile_granular_approval_policy_is_marked_experimental() {
-    let reason = crate::experimental_api::ExperimentalApi::experimental_reason(&Config {
-        model: None,
-        review_model: None,
-        model_context_window: None,
-        model_auto_compact_token_limit: None,
-        model_auto_compact_token_limit_scope: None,
-        model_provider: None,
-        approval_policy: None,
-        approvals_reviewer: None,
-        sandbox_mode: None,
-        sandbox_workspace_write: None,
-        forced_chatgpt_workspace_id: None,
-        forced_login_method: None,
-        web_search: None,
-        tools: None,
-        profile: None,
-        profiles: HashMap::from([(
-            "default".to_string(),
-            ProfileV2 {
-                model: None,
-                model_provider: None,
-                approval_policy: Some(AskForApproval::Granular {
-                    sandbox_approval: true,
-                    rules: false,
-                    skill_approval: false,
-                    request_permissions: false,
-                    mcp_elicitations: true,
-                }),
-                approvals_reviewer: None,
-                service_tier: None,
-                model_reasoning_effort: None,
-                model_reasoning_summary: None,
-                model_verbosity: None,
-                web_search: None,
-                tools: None,
-                chatgpt_base_url: None,
-                additional: HashMap::new(),
-            },
-        )]),
-        instructions: None,
-        developer_instructions: None,
-        compact_prompt: None,
-        model_reasoning_effort: None,
-        model_reasoning_summary: None,
-        model_verbosity: None,
-        service_tier: None,
-        analytics: None,
-        apps: None,
-        desktop: None,
-        additional: HashMap::new(),
-    });
-
-    assert_eq!(reason, Some("askForApproval.granular"));
-}
-
-#[test]
-fn config_nested_profile_approvals_reviewer_is_marked_experimental() {
-    let reason = crate::experimental_api::ExperimentalApi::experimental_reason(&Config {
-        model: None,
-        review_model: None,
-        model_context_window: None,
-        model_auto_compact_token_limit: None,
-        model_auto_compact_token_limit_scope: None,
-        model_provider: None,
-        approval_policy: None,
-        approvals_reviewer: None,
-        sandbox_mode: None,
-        sandbox_workspace_write: None,
-        forced_chatgpt_workspace_id: None,
-        forced_login_method: None,
-        web_search: None,
-        tools: None,
-        profile: None,
-        profiles: HashMap::from([(
-            "default".to_string(),
-            ProfileV2 {
-                model: None,
-                model_provider: None,
-                approval_policy: None,
-                approvals_reviewer: Some(ApprovalsReviewer::AutoReview),
-                service_tier: None,
-                model_reasoning_effort: None,
-                model_reasoning_summary: None,
-                model_verbosity: None,
-                web_search: None,
-                tools: None,
-                chatgpt_base_url: None,
-                additional: HashMap::new(),
-            },
-        )]),
         instructions: None,
         developer_instructions: None,
         compact_prompt: None,