Remove the legacy code-mode tool metadata inventory (#37500)

## What changed

- Stop adding `code_mode_tool_names` to Responses Lite turn metadata.
- Keep `code_mode_tool_names` reserved so client metadata cannot reintroduce the removed, unbounded inventory.
- Use the opt-in `tool_namespaces_info` metadata, including each function's `code_mode_name`, when authoritative tool details are requested.

## Testing

- Update Responses Lite and code-mode tests to verify the opt-in namespace metadata and normalized code-mode names.

GitOrigin-RevId: cbfb9af984de71c7cc175d0cd47ae799a5275309

codex-rs/core/tests/suite/agent_websocket.rs

@@ -79,29 +79,6 @@ async fn websocket_model_switch_to_responses_lite_omits_top_level_tools() -> Res
 
     assert_eq!(non_lite_turn["model"].as_str(), Some("gpt-5.2"));
     assert_eq!(lite_turn["model"].as_str(), Some("gpt-5.4"));
-    let non_lite_turn_metadata: Value = serde_json::from_str(
-        non_lite_turn["client_metadata"]["x-codex-turn-metadata"]
-            .as_str()
-            .expect("non-lite turn metadata"),
-    )?;
-    assert!(non_lite_turn_metadata.get("code_mode_tool_names").is_none());
-    let lite_turn_metadata: Value = serde_json::from_str(
-        lite_turn["client_metadata"]["x-codex-turn-metadata"]
-            .as_str()
-            .expect("Responses Lite turn metadata"),
-    )?;
-    assert_eq!(
-        lite_turn_metadata["code_mode_tool_names"]["view_image"],
-        serde_json::json!({
-            "name": "view_image",
-            "namespace": null,
-        })
-    );
-    assert!(
-        lite_turn["client_metadata"]
-            .get("x-codex-code-mode-tool-names")
-            .is_none()
-    );
     assert!(
         non_lite_turn
             .get("tools")

codex-rs/core/tests/suite/code_mode.rs

@@ -4853,6 +4853,7 @@ async fn code_mode_uses_the_first_dynamic_tool_for_a_normalized_name() -> Result
                 model_info.tool_mode = Some(ToolMode::CodeMode);
             })
             .with_config(|config| {
+                config.tool_registry.turn_metadata_includes_tool_info = true;
                 config
                     .features
                     .enable(Feature::CodeMode)
@@ -5041,18 +5042,9 @@ text(JSON.stringify({
                     .as_str()
                     .expect("Responses Lite should contain serialized turn metadata"),
             )?;
-            assert_eq!(
-                metadata["code_mode_tool_names"]["foo_bar"],
-                serde_json::json!({
-                    "name": "foo-bar",
-                    "namespace": null,
-                }),
-            );
-            assert!(
-                metadata["code_mode_tool_names"]
-                    .get("tool_search")
-                    .is_none()
-            );
+            let functions = &metadata["tool_namespaces_info"]["functions"]["functions"];
+            assert_eq!(functions["foo-bar"]["code_mode_name"], "foo_bar");
+            assert!(functions["foo_bar"]["code_mode_name"].is_null());
         }
 
         let exec_description = model_tools

codex-rs/core/tests/suite/responses_lite.rs

@@ -157,15 +157,7 @@ async fn responses_lite_uses_input_items_for_instructions_and_tools() -> Result<
             .context("Responses request should include turn metadata")?,
     )?;
 
-    assert_eq!(
-        turn_metadata["code_mode_tool_names"]["view_image"],
-        serde_json::json!({
-            "name": "view_image",
-            "namespace": null,
-        })
-    );
     assert!(turn_metadata.get("tool_namespaces_info").is_none());
-    assert!(!client_metadata.contains_key("x-codex-code-mode-tool-names"));
 
     Ok(())
 }