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/web/identity/presenters/src/lib/pages/login.page.scss

@@ -59,7 +59,7 @@
 
 .ts-login__lead {
   max-width: 46ch;
-  margin: 0 0 2.25rem;
+  margin: 0 0 0.75rem;
   font-size: 1.0625rem;
   line-height: 1.55;
   color: var(--ts-muted);
@@ -192,3 +192,19 @@
 .ts-login__form {
   row-gap: 1.75rem;
 }
+
+.ts-login__explore {
+  margin: 0 0 2.25rem;
+  font-size: 0.9375rem;
+  color: var(--ts-muted);
+
+  a {
+    font-weight: 600;
+    color: var(--ts-brand);
+    text-decoration: none;
+
+    &:hover {
+      text-decoration: underline;
+    }
+  }
+}

libs/web/identity/presenters/src/lib/pages/login.page.ts

@@ -1,3 +1,4 @@
+import { RouterLink } from '@angular/router';
 import {
   ChangeDetectionStrategy,
   Component,
@@ -85,6 +86,7 @@ const SAMPLE_FEED = [
   selector: 'ts-login-page',
   changeDetection: ChangeDetectionStrategy.OnPush,
   imports: [
+    RouterLink,
     LogoComponent,
     PiActionButtonComponent,
     PiDividerComponent,
@@ -109,6 +111,10 @@ const SAMPLE_FEED = [
           Bugs, cambios de UI, features y QA de tu equipo en un tablero que se
           mueve solo. Front, back y QA, enlazados de punta a punta.
         </p>
+        <p class="ts-login__explore">
+          ¿Solo quieres mirar?
+          <a routerLink="/explorar">Proyectos públicos →</a>
+        </p>
         <div class="ts-feed ts-panel" aria-hidden="true">
           <div class="ts-feed__track">
             @for (event of feed; track $index) {