feat: release notes

Each release can carry notes in Markdown, written before or after it
ships. A draft is generated from its finished tickets grouped by type, to
edit and copy from the releases page.

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

libs/api/tracker/application/src/lib/event-handlers/event-handlers.ts

@@ -32,6 +32,7 @@ import { IssueParentChangedEventHandler } from './issue-parent-changed.event-han
 import { IssueChecklistEventHandler } from './issue-checklist.event-handler';
 import { IssueRankedEventHandler } from './issue-ranked.event-handler';
 import { SprintEventHandler } from './sprint.event-handler';
+import { ReleaseNotesWrittenEventHandler } from './release-notes-written.event-handler';
 import { IssueSprintChangedEventHandler } from './issue-sprint-changed.event-handler';
 
 /** Read-model projections (MongoDB) + realtime, fed by the EventsBridge. */
@@ -69,6 +70,7 @@ export const EVENT_HANDLERS = [
   IssueChecklistEventHandler,
   IssueRankedEventHandler,
   SprintEventHandler,
+  ReleaseNotesWrittenEventHandler,
   IssueSprintChangedEventHandler,
 ];