Add per-event finance, event team permissions and public door sales state.

Event finance
- Finance tab on the event page: P&L summary with a revenue-to-result
  waterfall, costs and other income in one ledger, and the partner split
  with payouts. Lifecycle stepper (Selling, Adding costs, Ready to close,
  Finalized) with what is left to do; closing the books goes through a
  checklist dialog that freezes the numbers.
- Expense modal shows only the fields each calculation type needs, a live
  preview with the event's real counts, and a category suggested from the
  description. Date inputs follow the UI language.
- Global Finance page: profit per event with outliers clipped and labelled,
  and a "Ready to close" list of past events whose books are still open.
- Calculation service (integer PYG, basis points) with pinned regression
  scenarios; PYG formatting centralised in lib/money with locale-aware
  separators.

Event team permissions
- Per-event members with role presets and requireEventPermission; the
  header stat "Confirmed" is relabelled "Not checked in yet", which is
  what it counts.

Public sales state
- One sales state (online, door, sold out, ended, external, cancelled) for
  the event page, listings and JSON-LD, with the door price and tenders
  shown only while people can still pay at the door.

Frontend unit tests run with vitest (npm test in frontend/).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

backend/src/lib/capacity.ts

@@ -54,9 +54,11 @@ export function unseatedTicketCountQuery(executor: any, ticketIds: string[]) {
 /**
  * Query: per-event breakdown of paid vs claimed seats, grouped by event.
  * paidCount = confirmed + checked_in; claimedCount = pending_approval-held.
- * Pass `eventId` to restrict to one event (still returns a grouped row).
+ * Pass `eventId` to restrict to one event (still returns a grouped row), or an
+ * array of ids to restrict to those events (e.g. one page of a listing). Callers
+ * must skip the query for an empty array.
  */
-export function eventSeatBreakdownQuery(executor: any, eventId?: string) {
+export function eventSeatBreakdownQuery(executor: any, eventId?: string | string[]) {
   const query = executor
     .select({
       eventId: (tickets as any).eventId,
@@ -65,6 +67,8 @@ export function eventSeatBreakdownQuery(executor: any, eventId?: string) {
     })
     .from(tickets)
     .leftJoin(payments, eq((payments as any).ticketId, (tickets as any).id));
-  return (eventId ? query.where(eq((tickets as any).eventId, eventId)) : query)
-    .groupBy((tickets as any).eventId);
+  const scoped = Array.isArray(eventId)
+    ? query.where(inArray((tickets as any).eventId, eventId))
+    : eventId ? query.where(eq((tickets as any).eventId, eventId)) : query;
+  return scoped.groupBy((tickets as any).eventId);
 }