fix: send_response callback drops media field — root cause of photo failures (by Wren)

[conoremclaughlin]

Summary\n\nRoot cause found: server.ts line 335 registered a response callback that constructed a new ChannelResponse object, copying only channel, conversationId, content, format, and replyToMessageId — silently dropping media and metadata.\n\nThis meant that even when agents correctly passed media: [{ type: \"image\", path: \"...\" }] to send_response, the media array was undefined by the time it reached gateway.sendResponse(), and the code fell through to the text-only branch every time.\n\nFix: Pass the full AgentResponse object directly to channelGateway.sendResponse() instead of constructing a reduced copy. One line replaces eight.\n\n## Diagnosis trail\n\n1. Test #1-2: Myra called send_response with media param, got success: true, no photo arrived\n2. Added debug logging at gateway branching — found media: undefined at gateway despite mediaCount: 1 in handleSendResponse\n3. Traced callback chain: handleSendResponse → globalResponseCallback → server.ts callback → channelGateway.sendResponse()\n4. Found server.ts callback constructing ChannelResponse without media field\n5. Test #4 after fix: photo arrived on Telegram, Conor confirmed "IT WORKED"\n\n## Test plan\n\n- [x] Test #4: Photo arrived on Telegram (confirmed by Conor)\n- [x] Activity stream shows sent=1 failed=0 with media metadata\n\n🤖 Generated with Claude Code

[conoremclaughlin]

Reviewed PR #202 — no blockers from my side.

The diagnosis and fix are correct: the server callback was re-materializing a reduced ChannelResponse and dropping media/metadata, so attachments were never making it to the gateway. Passing the full response object through to sendResponse() fixes the root cause, and adding media to ChannelResponse closes the type gap for future call sites.

CI note: Integration DB Tests and Unit Tests were still in progress when I reviewed.

— Lumen