Paginate the admin events list.

The admin events page fetched every event on each load and rendered
them all, which grows without bound as the archive fills up. GET
/api/events now takes optional page and pageSize parameters and returns
total alongside the rows; pagination is opt-in, so the public pages and
the admin filter dropdowns that pass neither still get the full list
and the untouched response shape.

Page size is selectable (10/25/50/100) and deleting the last event on a
page falls back to the new last page instead of showing an empty table.
The ?edit=<id> deep link no longer depends on the target being in the
current page: when it is missing from the loaded rows the event is
fetched directly, guarded by a ref so the modal opens once.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

backend/src/routes/events.ts

@@ -172,6 +172,13 @@ const updateEventSchema = baseEventSchema.partial().refine(
 eventsRouter.get('/', async (c) => {
   const status = c.req.query('status');
   const upcoming = c.req.query('upcoming');
+  // Pagination is opt-in: callers that pass neither page nor pageSize (public
+  // pages, admin filter dropdowns) still get the full list.
+  const pageParam = c.req.query('page');
+  const pageSizeParam = c.req.query('pageSize');
+  const paginated = pageParam !== undefined || pageSizeParam !== undefined;
+  const page = Math.max(parseInt(pageParam || '1', 10) || 1, 1);
+  const pageSize = Math.min(Math.max(parseInt(pageSizeParam || '25', 10) || 25, 1), 200);
 
   // Only privileged users may see non-public events (drafts, archived, etc.).
   // Anonymous/regular callers are restricted to published events regardless of
@@ -195,12 +202,24 @@ eventsRouter.get('/', async (c) => {
     conditions.push(eq((events as any).status, 'published'));
   }
 
+  const whereClause = conditions.length === 0
+    ? undefined
+    : conditions.length === 1 ? conditions[0] : and(...conditions);
+
   let query = (db as any).select().from(events);
-  if (conditions.length > 0) {
-    query = query.where(conditions.length === 1 ? conditions[0] : and(...conditions));
+  if (whereClause) query = query.where(whereClause);
+  query = query.orderBy(desc((events as any).startDatetime));
+
+  let total: number | undefined;
+  if (paginated) {
+    let countQuery = (db as any).select({ count: sql`count(*)` }).from(events);
+    if (whereClause) countQuery = countQuery.where(whereClause);
+    const totalRow = await dbGet<any>(countQuery);
+    total = Number(totalRow?.count || 0);
+    query = query.limit(pageSize).offset((page - 1) * pageSize);
   }
-  
-  const result = await dbAll<any>(query.orderBy(desc((events as any).startDatetime)));
+
+  const result = await dbAll<any>(query);
 
   // Single grouped query for seat counts across all events (avoids N+1: previously
   // this ran one COUNT query per event). bookedCount = paid (confirmed/checked_in);
@@ -227,7 +246,9 @@ eventsRouter.get('/', async (c) => {
     };
   });
   
-  return c.json({ events: eventsWithCounts });
+  return paginated
+    ? c.json({ events: eventsWithCounts, total, page, pageSize })
+    : c.json({ events: eventsWithCounts });
 });
 
 // Get single event (public) - resolves by id, canonical slug, or historical alias