feat(board): Today card on top, chat bar pinned at the bottom (0.9.2)

[iamwhatever]

Summary

The owner's complaint: the daily report sat at the end of the Board while the chat sat at the top. The Board now reads, top to bottom:

1. Now strip (unchanged).
2. One thin line: Slack connection, last poll, Poll now (small button, same line).
3. Today: one card. The Lead's today one-liner is the heading; the latest digest's top items sit under it (Full digest unfolds the whole text); the header holds the digest date and Digest now. With no digest: No digest yet plus the button. What the digest contains is unchanged.
4. Needs you groups (unchanged from the slim Board).
5. Ask the lead… bar, collapsed, as the Board's last child, position: sticky; bottom: 0 inside the Board's scrolling panel. Same behaviour: one line + three quick questions, the first message opens the chat; opened, it grows upward from the bottom, and Collapse folds it back. The Lead's avatar dot still shows when it is working; the opened chat keeps its running line.

Connection line choice: a thin line right under the Now strip, not a fold into the Poller cell. It touches only Board and ConnectionLine (a new optional inline action); NowStrip and MemberStatus are shared with the Team tab and stay untouched.

Other changes:

• DigestCard becomes TodayCard; the today line moves out of NeedsCard. The button is Digest now (same POST /digest/request).
• No payload change, so desk/CONTRACT.md is untouched.
• README (EN + 中文) Board row, screenshot captions and the digest paragraph; desk/CHARTER.md Board order.
• app.json 0.9.2 + one highlights line.

Screenshots

docs/screenshots/board.png, chat-expanded.png, needs-you.png regenerated (plus the other frames the harness always rewrites).

Tested

• python -m pytest tests -q: 276 passed.
• npm run build: clean; ui/dist/index.mjs rebuilt.
• shoot.mjs: all checks ok. New checks:
  • order: Now strip < connection line < Today card < Needs you < chat bar in DOM order; the chat bar is the Board's last child, sticky, pinned to the bottom of the scrolling panel (collapsed and opened); opened, it grows upward with the same bottom edge; Collapse folds it back. Today card: title, the Lead's line, 2 top items, digest date, Digest now, no Request digest anywhere.
  • digest empty (?today=empty&digest=empty): No digest yet + Digest now, no items, no date, no heading.

Rebase note

Sibling PRs touch App.tsx and app.json (0.9.1 Now strip last-run + Watcher, 0.9.3 reply detail view). On rebase: keep the highest version and every highlights line, rebuild ui/dist, regenerate screenshots.