fix(mitm): getMitmStatus stub returns graceful status in Docker (#3390) - #3408

Review failed: Failed to connect to ingest: wss://cloud-agent-next.kilosessions.ai/sessions/oauth%2Fgoogle%3A111280339471504352511/agent_d1c5e5d6-bdb3-4aef-a81b-e08278e32bcc/ingest?wrapperRunId=wr_1a7825dc53b84228910a884c919c5dcc&kiloSessionId=&sessionId=agent_d1c5e5d6-bdb3-4aef-a81b-e08278e32bcc&wrapperGeneration=3&wrapperConnectionId=53af0bb3-cb47-4c67-9a72-b4f867b84972 (WebSocket error before open; Bun does not expose the HTTP status. If the Worker logs no /ingest request, check WORKER_URL and sandbox-to-host networking; if it logs a 4xx, inspect the DO rejection reason.)