face rooms: the Hide from sidebar a person chose is wiped by the next poll #2482

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: 1766ae351ab14ff1bfcd17e153f08356
Branch: dev/2-face-room-hide-persist
Base: f8ec27c
At: 2026-11-05T01:21:55Z

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

Written-by: FlyBot Lead

Symptom

In a face-to-face room, the Hide from sidebar switch is a dead control: turning it on hides the room for at most one poll (~4 s), then the room reappears, because every face snapshot upsert deletes room.hidden. The user's own choice is wiped once per facePollMs ?? 4_000.

Repro (live main f8ec27c2)

Open a face room whose home is a member of the room, toggle Hide from sidebar, wait one poll: the row is back. Same for turning it off — it comes back hidden. Red-first on a clean f8ec27c2 with only the new test file added:

not ok 1 - the hide a person chose outlives the next face-room poll
  error: |-
    the poll that re-upserts the open room keeps the hide
    + actual - expected
    + undefined
    - true
  code: 'ERR_ASSERTION'
not ok 2 - turning the switch back off survives the polls too
# tests 3 / # pass 1 / # fail 2

The third case (the #1605 rule) is already green: stale hidden left over from an older state must still be cleared.

Paths:

• write, once per poll: plugins/social/src/social.js:4106 applyFaceSnapshot → :4118 flybot.rooms.upsertFace(...) → core/src/host/hooks.js:1237 → core/src/host/room-membership.js:2903 upsertFaceRoom; on base the wipe is room-membership.js:2945 if (status !== 'closed' && status !== 'left') delete room.hidden
• read: core/src/client/sidebar.js:167 if (room.hidden && !active) return null; the switch reads room.hidden === true (core/src/client/group-settings.js:284)
• the user's toggle: actions.setFlags → core/src/host/channel.js:483 'set-flags' → core/src/host/roster.js:244 setFlags

Expected

A hide the user chose survives every poll for as long as the choice stands, and clearing it also survives; a stale hidden that no user set (the #1605 case) is still cleared by the same upsert. Existing hidden semantics, the API and every client-visible field stay unchanged, and the #1605 tests stay green unmodified.

Design (the slice we will implement)

setFlags stamps room.hiddenAt when a person hides the room and removes it when they unhide; upsertFaceRoom only does delete room.hidden when that stamp is absent. state.rooms[id] gains one optional numeric field; no STATE_VERSION bump and no migration (an old file without the field keeps today's behaviour).

Scope

• core/src/host/room-membership.js (the decision, +1/−1)
• core/src/host/roster.js (the stamp, +9/−1)
• core/test/face-room-hidden.test.js (new, 3 cases)
• docs/subsystems/core-host.md (+1, for arch-docs)
• regenerated patches/ds-bot/** via generate (generated, never edited by hand)

Does not touch core/client.js, patches/ds-bot/0008, or plugins/social/client.js; host lane only.

Rejected alternative: removing the Hide switch from the client. That is the client lane, and it deletes a working control instead of making it work.

Dedupe (2026-11-05)

GitHub search on live main: face room hidden (41, only #1821 open — about remote seats appearing in the sidebar, not about the hide persisting), Hide from sidebar (77, nothing matching), hiddenAt (1, #2231 closed, read-only read endpoints), upsertFaceRoom (9, all closed except the same three above). The only related rule is closed #1605 (clear a stale hidden), which this issue keeps intact. No open PR touches room-membership.js or roster.js; no live claim.