Preserve MCP tool-list metadata in server status (#54686)

## Why

MCP tool discovery discarded response-level `_meta`, leaving server-status clients unable to inspect metadata associated with the tool catalog.

## What changed

- Preserve opaque `_meta` from the first `tools/list` page through catalog refreshes and caches.
- Expose it as `toolListMeta` in `McpServerStatus`, with `null` when unavailable, and update generated schemas and bindings.
- Scope cached Apps catalog metadata to discovery settings, including client capabilities and extensions, while retaining tools from older caches without metadata.
- Restrict server capabilities in status snapshots to the selected servers.

## Testing

Add regression coverage for listing legacy cached Apps tools during failed startup, and update protocol serialization expectations for nullable `toolListMeta`.

GitOrigin-RevId: 62335e2fd8c482067a7a78a7612b58c3eaa9fb55

sdk/python/src/openai_codex/generated/v2_all.py

@@ -8839,6 +8839,13 @@ class McpServerStatus(BaseModel):
         ),
     ] = None
     server_info: Annotated[McpServerInfo | None, Field(alias="serverInfo")] = None
+    tool_list_meta: Annotated[
+        Any | None,
+        Field(
+            alias="toolListMeta",
+            description="Opaque `_meta` from the first page of the corresponding MCP tool catalog. Null when unavailable.",
+        ),
+    ] = None
     tools: dict[str, Tool]
     tools_error: Annotated[
         str | None,