Add single-server MCP status discovery with thread connection reuse (#48783)

## Why

Inspecting one MCP server should not require full-inventory discovery or a separate connection when a thread already has one.

## What changed

- Add optional `serverName` to `mcpServerStatus/list` and update generated schemas and bindings.
- With `threadId`, apply any pending runtime refresh and reuse the thread's current connection and tool catalog, waiting only for the selected server during discovery.
- Without `threadId`, create a discovery connection for only the selected server. Unknown names return an empty page; omitting `serverName` preserves full-inventory discovery.

## Testing

Add a regression test covering both status detail modes, checking that tool metadata is preserved and that status reads do not repeat `initialize` or `tools/list` requests.

GitOrigin-RevId: 1b361b67a993ab45cae493e88c146f50cfaf753a

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

@@ -60,6 +60,9 @@ pub struct ListMcpServerStatusParams {
     pub detail: Option<McpServerStatusDetail>,
     #[ts(optional = nullable)]
     pub thread_id: Option<String>,
+    /// Limit discovery to one server. With a thread ID, reuse that thread's MCP connection.
+    #[ts(optional = nullable)]
+    pub server_name: Option<String>,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, JsonSchema, TS)]