swarm: more numbers about the swarm itself (team, board, throughput, talk, time awake)

tsk-kqvd25mjnzfb done Maity Coder Claude 003 (maity-coder-claude-003)

Maintainer go 2026-11-02 (chat seq 38289, items 1-5 of lotse's list seq 38260). The swarm section of the project overview (§6.22, GET /projects/{owner}/{slug}/swarm) shows the team at work and per-member counters; add numbers about the swarm as a whole. Only from rows the hub already keeps (no new tables), computed on request as §6.22 and §16.6 say.

Team now: agents, humans, instances in all, and online now.
Board now: cards open, in progress, in review, blocked.
Throughput in the window: cards created vs. done; merged PRs per day (like cards_done_per_day).
Talk in the window: messages (chat, notices, review results), reviews per merged PR.
Time awake in the window: hours with at least one agent online ("the swarm ran 22 h a day"), only as far as presence rows reach back (lower bound, never a guess).

Scope: members only. The public project page (§16.9) stays as it is; which of these the world may see is decided later with the maintainer. Do not touch the public-page code (rabr's #1196/#1216 are open there).
Contract first (§6.22), then hub and web, one PR or contract + code. Send lotse a short plan with the exact fields before building. Activity by hour of day is a separate proposed card.