feat: a public notes page per release, for clients

On the releases page, «Página pública» (owners and admins) opens a
secret link to a page with the release's notes, readable without an
account, also for private projects: the notes written, or the draft
from its finished tickets while there are none (without repeating the
title the page already shows). The link can be copied, renewed (the old
one stops working) or withdrawn. Stored in Mongo (`release_note_shares`).

API: shareReleaseNotes / unshareReleaseNotes / releaseNotesShare,
publicReleaseNotes(token); GET/PUT/DELETE /api/releases/{id}/public-notes,
GET /api/shared/release-notes/{token}. Web: /notes/:token.

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

libs/api/tracker/infrastructure/src/lib/mongo/read-model.schemas.ts

@@ -112,6 +112,7 @@ export const ReadModels = {
   TreeFollow: 'TreeFollow',
   IssueReminder: 'IssueReminder',
   MyDay: 'MyDay',
+  ReleaseNotesShare: 'ReleaseNotesShare',
   Sprint: 'SprintReadModel',
   GitIntegration: 'GitIntegration',
   OutgoingWebhook: 'OutgoingWebhook',
@@ -395,6 +396,15 @@ class MyDayDocument {
 export const MyDaySchema = SchemaFactory.createForClass(MyDayDocument);
 MyDaySchema.index({ userId: 1, day: -1 }, { unique: true });
 
+@Schema({ ...LOOSE, collection: 'release_note_shares' })
+class ReleaseNotesShareDocument {
+  @Prop({ type: String, required: true, unique: true }) releaseId!: string;
+  @Prop({ type: String, required: true, unique: true }) token!: string;
+}
+export const ReleaseNotesShareSchema = SchemaFactory.createForClass(
+  ReleaseNotesShareDocument,
+);
+
 @Schema({ ...LOOSE, collection: 'git_integrations' })
 class GitIntegrationDocument {
   /** The project's id. */
@@ -503,6 +513,7 @@ export const READ_MODEL_SCHEMAS = [
   { name: ReadModels.TreeFollow, schema: TreeFollowSchema },
   { name: ReadModels.IssueReminder, schema: IssueReminderSchema },
   { name: ReadModels.MyDay, schema: MyDaySchema },
+  { name: ReadModels.ReleaseNotesShare, schema: ReleaseNotesShareSchema },
   { name: ReadModels.CalendarFeed, schema: CalendarFeedSchema },
   { name: ReadModels.DashboardShare, schema: DashboardShareSchema },
   { name: ReadModels.PushSubscription, schema: PushSubscriptionSchema },