v0.5.0

Changed

• Fetcher live poll now uses conditional requests (ETag / If-None-Match). The per-repo deployments list and in-flight deployment status re-reads send If-None-Match; an unchanged response comes back 304 Not Modified, which does not count against the GitHub rate limit. Building on the terminal-deployment skip from 0.4.0, an idle poll cycle now returns cheap 304s instead of re-downloading the deployments list and statuses. Parent-deployment edges are preserved across cycles, and the optimization degrades gracefully to full fetches when the upstream does not supply ETags (e.g. the github-emulator). (Implements Fetcher spec F8.)