Port recent OpenRoomote changes (#547, #548)

[mrubens]

Ports the two OpenRoomote changes that landed after this repo's split point (OpenRoomote #544), cherry-picked with original authorship preserved.

Changes

1. Slack behavior eval runner (RooCodeInc/OpenRoomote#547) — criterion-based eval scenarios driven through the mock Slack harness: a new eval:scenario script in packages/slack, the runner at packages/slack/evals/run-slack-scenario.ts, two starter scenarios (!fast answer quality, duplicate-delivery dedup), and a guidance doc at .agent-guidance/operations/slack-behavior-evals.md. Applied cleanly.
2. Render first-boot race fix (RooCodeInc/OpenRoomote#548) — self-referencing hostname fallback to RENDER_EXTERNAL_HOSTNAME in .docker/app/entrypoint.sh plus a troubleshooting section in deploy/render/README.md. The README hunk auto-merged against this repo's diverged copy; reviewed and correct in context.

How the port was scoped

This repo was cut from OpenRoomote with history squashed, so the split point was located by scanning OpenRoomote history for the commit whose tree is closest to this repo's initial commit: OpenRoomote affc9a93 (#544). The remaining ~80-file baseline difference is the intentional split transformation (squashed Drizzle migrations, removed cli/email packages, deploy/docs/CI edits). Only these two commits postdate it.

Validation

• @roomote/slack typecheck and lint pass; Prettier clean on all ported files
• sh -n syntax check on the entrypoint script
• Pre-push hooks (lint:fast, check-types:fast, knip) passed

[roomote-roomote-v1]

No code issues found. See task

Reviewed both ported changes against the current repo state:

• Slack eval runner (packages/slack/evals/run-slack-scenario.ts) — the runner's use of MockSlackServer (constructor, start/dispatch/getState/stop) and every state field it reads (messages, botUserId, botId, bot_id) matches mock-slack-server.ts. Token substitution, the url_verification preflight, and the settle/timeout loop are correct. Scenario JSONs are consistent with their criteria.
• Render first-boot fix (.docker/app/entrypoint.sh) — the RENDER_EXTERNAL_HOSTNAME fallback uses POSIX :="${...:-}" defaults that are safe under set -eu, runs before the URL-derivation block, and only heals the self-referencing case, matching the deploy/render/README.md note.

Clean, well-scoped port.

[github-actions]

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[mrubens]

I have read the CLA Document and I hereby sign the CLA

[daniel-lxs]

I have read the CLA Document and I hereby sign the CLA