A Bot board's Done column empties after switching Bots in the rail: the archive page is still read for the Bot you left #2070

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment on this issue.

Written-by: FlyBot Lead
Claimed-by: FlyBot Lead
Claim-Id: ec4ccab8d07f491eb506ffe0f6bbcb7a
Branch: dev/3-board-bot-switch-archive
Base: 5b862c6
At: 2026-11-01T17:55:34Z

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment.
Written-by: FlyBot Lead

What happens today

Click another Bot in the board's rail and its Done column empties, although that Bot has finished cards and its archive page holds them.

core/src/client/kanban.js on 5b862c6e:

• :170 — const key = scope?.kind === 'group' ? \group:${scope.roomId}` : 'own'`. Every Bot scope produces the same key, so moving from Bot A to Bot B does not change it.
• :198 — the board effect's dependency array is [key] alone, so switching Bots does not re-run it: no new read is issued.
• :179 — const archiveQuery = scope?.kind === 'bot' ? { botId: scope.botId } : query is evaluated once per (non-re-)run, so it keeps the previous Bot's botId.
• :190 — the archive page read therefore asks for the old Bot's page; the 15 s poll inside the same effect keeps doing so.
• :207 — const done = scope?.kind === 'group' ? archive : archive.filter(task => !scope?.botId || task.ownerBotId === scope.botId) filters that old page by the new scope, so nothing survives: the Done column renders empty until the user happens to switch back or reload.

The room scope is the reason this reads as "Done is fine"; it is /group:<roomId> and does re-run. Only the Bot-to-Bot switch is broken.

Reproduction (red first, on live main 5b862c6e)

Harness-level, after a Bot board and a second Bot with one done card in its archive page:

1. Render the board with scope { kind: 'bot', botId: 'a' } whose archive page returns a done card owned by a; the Done column draws it.
2. Re-render with scope { kind: 'bot', botId: 'b' }, whose archive page ({ botId: 'b', archive: true, limit: 20 }) returns a done card owned by b.
3. Today: zero done cards are drawn — the effect did not re-run, and what it holds was read for a and is then filtered by b.
4. Expected: the Done column draws b's done card. The read is issued with { botId: 'b', archive: true, limit: 20 }.

The control that must stay green: the same sequence for a → b → a, and a group scope ({ kind: 'group', roomId }) that still reads its archive on entering the room.

Red first, measured on live main 5b862c6e

With only the new test file in place (source untouched), three runs read # tests 15 / pass 14 / fail 1, failing exactly P-360: switching the rail re-reads the archive, and the new Bot draws its own Done page on switching to Writer asks for Writer's archive page — archiveReads() is ['a'] where ['a','s'] is required, i.e. clicking Bot B issues no new archive read at all. The case drives a real stateful hook runtime (hook slots per component path, effect re-run only when deps change, setter-driven re-render, fake 15 s clock) rather than the top-of-file stub that never re-runs an effect (#1810).

Mutations that must go red on top of the fix: the key reverted to 'own' (three runs 15/14/1, same failure), and the archive query read from a ref holding the new scope while the dependency array keeps the old key (same failure — no re-read on a switch).

Expected behaviour and scope

• The board effect re-runs when the Bot changes; the archive read names the Bot now being shown; the Done column reflects that Bot's finished cards.
• Scope: core/src/client/kanban.js (the key, one line plus comment), core/test/kanban.test.js, core/client.js and the matching patches/ds-bot/ mirror (0008, files/src/client, files/test) regenerated by the script rather than hand-edited, one line in docs/subsystems/core-client.md next to the P-364 note, and one changelog.d/ fragment.
• Out of scope: kanban.js:401's Done total (#2069), the Done page's pagination (P-361), the silent read failure (P-370), and the Done column's missing finish time (#2066). Separate issues; do not widen this one.

Dedupe

Searched live main 5b862c6e and the closed issues for board/archive/Done switching: #2045 and #2048 (closed, the archive page printed as the Done total), #2063 (closed, a room rail counting only its archive page), #2066 (open, the Done column not showing when a card finished), #1793/#818 (retired Bot, archived section border — unrelated). Nothing open covers a Bot switch leaving the Done column empty.

Acceptance

• A failing test first, on 5b862c6e, whose failure names this behaviour (not an import error).
• Two mutation arms: reverting the key to 'own' must turn the new test red; keeping the key fixed but leaving the archive query closed over the previous scope must turn it red too.
• TZ=UTC ARCH_DOCS_BASE=5b862c6e npm run verify green, build-client --check 0, ds-bot-patches check clean (core/ equals ds-bot/ plus patches), changelog.mjs check green.