Remove core MCP list tools op (#21281)

## Why

The core `Op::ListMcpTools` request path is no longer needed. Keeping it
around left a dead request/response surface alongside the app-server MCP
inventory APIs that own current server status listing.

## What Changed

- Removed `Op::ListMcpTools`, `EventMsg::McpListToolsResponse`, and the
core handler that built the MCP snapshot response.
- Removed the now-unused `codex-mcp` snapshot wrapper/export and passive
event handling arms in rollout and MCP-server consumers.
- Updated tests that used the old op as a synchronization hook to wait
on existing startup/skills events, and deleted the plugin test that only
exercised the removed listing op.

## Validation

- `cargo test -p codex-protocol`
- `cargo test -p codex-mcp`
- `cargo test -p codex-rollout -p codex-rollout-trace -p
codex-mcp-server`
- `cargo test -p codex-core --test all
pending_input::queued_inter_agent_mail`
- `cargo test -p codex-core --test all
rmcp_client::stdio_mcp_tool_call_includes_sandbox_state_meta`
- `cargo test -p codex-core --test all
rmcp_client::stdio_image_responses`
- `just fix -p codex-core -p codex-protocol -p codex-mcp -p
codex-rollout -p codex-rollout-trace -p codex-mcp-server`

codex-rs/codex-mcp/src/mcp/mod.rs

@@ -31,7 +31,6 @@ use codex_protocol::mcp::Tool;
 use codex_protocol::models::PermissionProfile;
 use codex_protocol::protocol::AskForApproval;
 use codex_protocol::protocol::McpAuthStatus;
-use codex_protocol::protocol::McpListToolsResponseEvent;
 use rmcp::model::ReadResourceRequestParams;
 use rmcp::model::ReadResourceResult;
 use serde_json::Value;
@@ -347,18 +346,6 @@ pub async fn collect_mcp_server_status_snapshot_with_detail(
     snapshot
 }
 
-pub async fn collect_mcp_snapshot_from_manager(
-    mcp_connection_manager: &McpConnectionManager,
-    auth_status_entries: HashMap<String, McpAuthStatusEntry>,
-) -> McpListToolsResponseEvent {
-    collect_mcp_snapshot_from_manager_with_detail(
-        mcp_connection_manager,
-        auth_status_entries,
-        McpSnapshotDetail::Full,
-    )
-    .await
-}
-
 pub(crate) fn codex_apps_mcp_url(config: &McpConfig) -> String {
     codex_apps_mcp_url_for_base_url(
         &config.chatgpt_base_url,
@@ -595,44 +582,6 @@ async fn collect_mcp_server_status_snapshot_from_manager(
     }
 }
 
-async fn collect_mcp_snapshot_from_manager_with_detail(
-    mcp_connection_manager: &McpConnectionManager,
-    auth_status_entries: HashMap<String, McpAuthStatusEntry>,
-    detail: McpSnapshotDetail,
-) -> McpListToolsResponseEvent {
-    let (tools, resources, resource_templates) = tokio::join!(
-        mcp_connection_manager.list_all_tools(),
-        async {
-            if detail.include_resources() {
-                mcp_connection_manager.list_all_resources().await
-            } else {
-                HashMap::new()
-            }
-        },
-        async {
-            if detail.include_resources() {
-                mcp_connection_manager.list_all_resource_templates().await
-            } else {
-                HashMap::new()
-            }
-        },
-    );
-
-    let tools = tools
-        .into_iter()
-        .filter_map(|(name, tool)| {
-            protocol_tool_from_rmcp_tool(&name, &tool.tool).map(|tool| (name, tool))
-        })
-        .collect::<HashMap<_, _>>();
-
-    McpListToolsResponseEvent {
-        tools,
-        resources: convert_mcp_resources(resources),
-        resource_templates: convert_mcp_resource_templates(resource_templates),
-        auth_statuses: auth_statuses_from_entries(&auth_status_entries),
-    }
-}
-
 #[cfg(test)]
 #[path = "mod_tests.rs"]
 mod tests;