[semics-tech]

Origin: requested by Oli (job 97, retry of job 90).

Adds .github/workflows/compose-smoke.yml, which brings up deploy/docker-compose.demo.yml on a clean runner and checks that it works end to end.

• Triggers: pull_request, push to main, and manual workflow_dispatch.
• permissions: contents: read. No secrets are used.
• 20 minute timeout, with a concurrency group that cancels superseded runs.
• Starts with docker compose up -d rather than --wait, because the one-shot certs and seed services exit by design. A poll loop replaces it.
• Polls the dashboard on http://localhost:8080 until it answers, then checks that / serves HTML.
• Logs in as the demo admin, which uses the throwaway credentials already published in the compose file. It polls /api/workers until DEMO-SQLHOST01 is online.
• Writes the startup duration to $GITHUB_STEP_SUMMARY.
• On failure it prints compose ps -a and the last 200 log lines per service.
• It always runs down -v.

The /api/workers field names (hostName, online) were checked against packages/server/src/api/app.ts and the DB schema.

The SQL Server image is amd64, so the runner pulls about 1.5 GB and the first run may be slow.

🤖 Generated with Claude Code

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Draft opened by Oli's repos agent.