502 error reporting tasks via MCP

Inside the workspace:

```sh
⎿ Error: MCP error -32603: PATCH
https://demo.coder.com/api/v2/workspaceagents/me/app-status: unexpected
status code 502: unexpected non-JSON response ""
Error: no response body
```

Using `main` branch commit https://github.com/coder/coder/commit/51ed624bb953267a6ad8183fd8896dca34da74a3

coderd logs
```sh
Jun 04 22:31:26 ip-172-31-12-44 coder[300861]: 2025-06-04 22:31:26.435 [warn] coderd: GET host=preview--dev--task-1749076106571--ben.demo.coder.com path=/ proto=HTTP/1.1 remote_addr=127.0.0.1 start="2025-06-04T22:31:26.404280198Z" requestor_name="Crypto Key Reader" took=31.329585ms status_code=502 latency_ms=31 request_id=b8e4e8e6-029d-4489-959c-e38cdb49261a ...
```