feat: Client-published events + realtime presence

- POST /projects/:id/events accepts client-authored events restricted to
  the custom.* namespace — system types can't be spoofed. They flow
  through the same publishEvent fan-out: realtime, webhooks, and
  event_pattern functions all fire.
- Presence: subscribe/unsubscribe bumps a per-project count and
  broadcasts presence.update {online} to the realtime stream only —
  deliberately not through publishEvent so webhooks and "*" functions
  don't fire on connect noise. GET …/realtime/presence reads the count.
- @primora/client gains publish() and presence(); CLI gains events:send.

Verified live: presence 0->1 on subscribe, presence.update frame
delivered, custom event delivered to SSE + fired a custom.* function,
spoofed document.created rejected 400.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

packages/api-client/src/generated/index.ts

@@ -117,6 +117,7 @@ export type { ProjectOverview } from './models/ProjectOverview';
 export type { ProjectSecret } from './models/ProjectSecret';
 export type { ProjectSecretListResponse } from './models/ProjectSecretListResponse';
 export type { ProjectSummary } from './models/ProjectSummary';
+export type { PublishEventRequest } from './models/PublishEventRequest';
 export type { ReadinessStatus } from './models/ReadinessStatus';
 export type { RevealProjectSecretResponse } from './models/RevealProjectSecretResponse';
 export type { RybbitMetricItem } from './models/RybbitMetricItem';
@@ -269,6 +270,7 @@ export { $ProjectOverview } from './schemas/$ProjectOverview';
 export { $ProjectSecret } from './schemas/$ProjectSecret';
 export { $ProjectSecretListResponse } from './schemas/$ProjectSecretListResponse';
 export { $ProjectSummary } from './schemas/$ProjectSummary';
+export { $PublishEventRequest } from './schemas/$PublishEventRequest';
 export { $ReadinessStatus } from './schemas/$ReadinessStatus';
 export { $RevealProjectSecretResponse } from './schemas/$RevealProjectSecretResponse';
 export { $RybbitMetricItem } from './schemas/$RybbitMetricItem';