fix(dashboard): take the booker's name from the owner's read, not the event

[simonorzel26]

Companion to open-deltat/deltat#49 (merged), which stops change notifications carrying booking labels: a label is whatever the booker typed, often their name, and every subscriber on a calendar heard it. On delt.at that includes any browser watching a public booking page, through the demo's WebSocket bridge.

The owner dashboard (demo/components/dashboard/live-schedule.tsx) displayed the name straight from the BookingConfirmed event, so against a kernel with #49 a live booking would show no name until a reload.

Change

• Names come from one place, the owner's read (getCalendar, the same owner-checked action the page loads with). A booking's name never changes, so every reply adds to a single name lookup that the day view, month view and activity log all read. A cancelled booking's log line keeps its name.
• Events still show a change the moment it happens; the read then says which bookings exist. A read goes out at most 200 ms after the first change of a burst (it does not reset on every change, so steady traffic cannot starve it). Its booking list lands only if no change came in after it was sent, so a slow reply cannot undo what a later event showed; that change has already asked for the next read. Names from an overtaken reply still land.
• Also reads on Lagged and whenever the stream (re)connects (mount, back from another tab, after a reconnect), since each means changes may have been missed. Before this, a tab switch brought back the page-load list and nothing corrected it.
• A failed read, or one after the session expired, keeps what the events showed.

Works against kernels before and after #49 (the event's label is not used either way).

Checks

• tsc --noEmit on the demo passes; bun test 469 pass, 0 fail.
• Traced by hand: a single booking, two bookings with a read in flight, steady 150 ms traffic, a cancel overtaking a read.
• Not exercised in a browser: the dashboard needs a real OIDC sign-in and there is no local bypass. To check after deploy: open a calendar's dashboard, book it from its public page in another window, and the name appears within a moment.

Left for later: a visible hint when reads keep failing (expired session), a per-principal rate limit on getCalendar now that the browser calls it, a narrower read than the whole calendar, and sharing the debounce with the hotel and stadium examples.

🤖 Generated with Claude Code

https://claude.ai/code/session_01Vaz5XtKxcGVsLe9GeX186M