feat: public projects, project deletion and sagas

Public projects:
- Project.isPublic (create/update, owners and admins). Anyone can read a
  public project without a token: project, board, tickets, comments,
  history, releases, activity, tracking and statistics, over GraphQL and
  REST. Writes stay for members (401 anonymous, 403 outsiders).
- @OptionalAuth() / @ApiOptionalPireonAuth(): anonymous callers allowed,
  invalid tokens still rejected. ReadAccess lets anonymous viewers read
  public projects only; linked tickets are filtered by visibility.
- publicProjects (GraphQL) and GET /api/explore/projects (REST).
- Web: «Explorar» page, project pages open without a session (read-only
  notice, sign-in hints), public badge, visibility switch in settings,
  no realtime subscriptions without a session.

Project deletion:
- Owner only, confirming the key (deleteProject / DELETE
  /api/projects/{project}?confirm=KEY). The key is freed; the read model
  drops the project and members are notified (web goes home).

Sagas (run by the EventsBridge after projections, durable and ordered):
- ProjectDeletionSaga: project deleted → delete its tickets and releases;
  ticket deleted → purge its comments and drop links from other tickets.
- ReleaseArchivedSaga: unfinished tickets leave an archived release.
- UserDeactivatedSaga: the Pireon webhook records UserDeactivatedEvent in
  the event store (EventRecorder); the tracker unassigns that user's open
  tickets as the system actor.
- Internal idempotent commands; domain refusals are logged and skipped,
  concurrency conflicts retried. Affected streams come from the event store
  (TrackerStreamsRepository).

Tests: domain lifecycle specs, saga specs run like the bridge, facade
tests, e2e for public access, cascade deletion, archived releases and
deactivation webhook. Docs, READMEs, schema.gql/openapi.json and Word/PDF
updated.

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

libs/api/tracker/application/src/lib/queries/get-issues-by-ids.query-handler.ts

@@ -1,7 +1,7 @@
 import { IQueryHandler, QueryHandler } from '@nestjs/cqrs';
 import { IssueReadModel } from '@task-stream/api/tracker/domain';
 import { FindIssuesRepository } from '../ports/find-issues.repository';
-import { FindProjectsRepository } from '../ports/find-projects.repository';
+import { ReadAccess } from './read-access';
 import { GetIssuesByIdsQuery } from './get-issues-by-ids.query';
 
 @QueryHandler(GetIssuesByIdsQuery)
@@ -10,14 +10,19 @@ export class GetIssuesByIdsQueryHandler
 {
   constructor(
     private readonly findIssues: FindIssuesRepository,
-    private readonly findProjects: FindProjectsRepository,
+    private readonly access: ReadAccess,
   ) {}
 
   async execute(query: GetIssuesByIdsQuery): Promise<IssueReadModel[]> {
     const issues = await this.findIssues.findByIds([...new Set(query.ids)]);
-    const visible = new Set(
-      (await this.findProjects.findByMember(query.viewerId)).map((p) => p.id),
-    );
-    return issues.filter((issue) => visible.has(issue.projectId));
+    // Linked tickets may sit in other projects: keep the ones the viewer can read.
+    const visible = new Map<string, boolean>();
+    for (const projectId of new Set(issues.map((issue) => issue.projectId))) {
+      visible.set(
+        projectId,
+        await this.access.canView(projectId, query.viewerId),
+      );
+    }
+    return issues.filter((issue) => visible.get(issue.projectId));
   }
 }