fix(support): agent-demo self-seeds (join default queue + go online); tickets always get a queue

Root cause of 'waiting for escalations': no queue/membership meant tickets were
never assigned. Now: createTicket find-or-creates a default queue; new joinDefault
endpoint + useGoOnline hook; agent-demo joins+goes-AVAILABLE on load (assignPending
picks up any waiting ticket). smoke-support self-seeds (no seed script needed).
Also: vitest singleFork to end cross-file DB races (45 tests deterministic).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/iios-service/src/support/support.service.ts

@@ -40,10 +40,14 @@ export class SupportService {
     const requester = await this.actors.resolveActor(scope.id, principal);
     const traceId = randomUUID();
 
-    // Default to the scope's first enabled queue so assignment has candidates.
+    // Every ticket gets a queue so assignment has somewhere to route it — find
+    // the scope's default queue or create one.
     const queueId =
       input.queueId ??
-      (await this.prisma.iiosSupportQueue.findFirst({ where: { scopeId: scope.id, enabled: true } }))?.id;
+      (
+        (await this.prisma.iiosSupportQueue.findFirst({ where: { scopeId: scope.id, enabled: true } })) ??
+        (await this.prisma.iiosSupportQueue.create({ data: { scopeId: scope.id, name: 'Support' } }))
+      ).id;
 
     return this.prisma.$transaction(async (tx) => {
       const ticket = await tx.iiosTicket.create({