Wires the Phase 1 sqlite store into the dashboard HTTP layer so the
frontend can surface full build logs without hitting journald.
Two new read endpoints:
- GET /api/build-logs/{agent}?limit=N — Vec<BuildLogHeader> JSON,
newest first, default limit 10, server-side cap at 50.
- GET /api/build-logs/id/{id} — BuildLogFull JSON (header +
stdout + stderr), HTTP 404 on vacuum-reaped / unknown ids.
Agent-name validated ([a-z0-9_-], 1-63 chars) before the sqlite call.
Both handlers reach coord.build_logs (Arc<BuildLogs>) introduced in
the Phase 1 commit. Docs updated in docs/web-ui.md.
f6b3145349