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/tracker/presenters/src/lib/pages/project-shell.page.ts

@@ -6,14 +6,20 @@ import {
   inject,
   input,
 } from '@angular/core';
-import { RouterLink, RouterLinkActive, RouterOutlet } from '@angular/router';
+import {
+  Router,
+  RouterLink,
+  RouterLinkActive,
+  RouterOutlet,
+} from '@angular/router';
+import { AuthFacade } from '@task-stream/web/identity/application';
 import { PiNoteComponent, PiSpinnerComponent } from '@pi/ui';
 import {
   ProjectFacade,
   provideProjectFacade,
 } from '@task-stream/web/tracker/application';
 import { AvatarsComponent } from '../ui/avatars';
-import { projectTone, ROLE } from '../ui/copy';
+import { projectTone, PUBLIC_TONE, ROLE } from '../ui/copy';
 
 /** /p/:key — loads the project once for all its tabs (its store and facade are scoped here). */
 @Component({
@@ -33,11 +39,18 @@ import { projectTone, ROLE } from '../ui/copy';
       <header class="ts-project-header" [style.--tone]="tone(project.key)">
         <div class="ts-project-header__main">
           <p class="ts-eyebrow">
-            <a class="ts-plain-link" routerLink="/">Proyectos</a> /
+            @if (auth.isAuthenticated()) {
+              <a class="ts-plain-link" routerLink="/">Proyectos</a> /
+            } @else {
+              <a class="ts-plain-link" routerLink="/explorar">Explorar</a> /
+            }
             {{ project.key }}
             @if (facade.myRole(); as role) {
               · {{ roleLabel(role) }}
             }
+            @if (project.isPublic) {
+              <span class="ts-pill" [style.--tone]="publicTone">Público</span>
+            }
           </p>
           <h1>
             <span class="ts-project-header__key">{{ project.key }}</span>
@@ -56,6 +69,20 @@ import { projectTone, ROLE } from '../ui/copy';
           >
         </div>
       </header>
+      @if (!facade.myRole()) {
+        <p class="ts-readonly" role="note">
+          Proyecto público: lo estás viendo en modo lectura.
+          @if (!auth.isAuthenticated()) {
+            <a
+              class="ts-plain-link"
+              routerLink="/login"
+              [queryParams]="{ returnUrl: url() }"
+              >Inicia sesión</a
+            >
+            si eres del equipo.
+          }
+        </p>
+      }
       <nav class="ts-tabs" aria-label="Secciones del proyecto">
         <a routerLink="board" routerLinkActive="is-active">Tablero</a>
         <a routerLink="releases" routerLinkActive="is-active">Releases</a>
@@ -77,8 +104,26 @@ import { projectTone, ROLE } from '../ui/copy';
         appearance="fill"
         type="status"
         title="No se pudo abrir el proyecto"
-        [text]="error"
+        [text]="
+          auth.isAuthenticated()
+            ? error
+            : 'No existe o no es público. Si es de tu equipo, inicia sesión.'
+        "
       />
+      @if (!auth.isAuthenticated()) {
+        <p class="ts-center-actions">
+          <a
+            class="ts-plain-link"
+            routerLink="/login"
+            [queryParams]="{ returnUrl: url() }"
+            >Iniciar sesión</a
+          >
+          ·
+          <a class="ts-plain-link" routerLink="/explorar"
+            >Ver proyectos públicos</a
+          >
+        </p>
+      }
     } @else {
       <div class="ts-center">
         <pi-spinner [isLoading]="true" [diameter]="40" />
@@ -86,6 +131,33 @@ import { projectTone, ROLE } from '../ui/copy';
     }
   `,
   styles: `
+    .ts-eyebrow .ts-pill {
+      margin-left: 0.5rem;
+      letter-spacing: 0;
+      text-transform: none;
+      vertical-align: middle;
+    }
+    .ts-readonly {
+      margin: 1rem 0 0;
+      padding: 0.625rem 0.875rem;
+      border-radius: 0.625rem;
+      background: color-mix(in srgb, var(--ts-c-teal) 8%, var(--ts-surface));
+      border: 1px solid color-mix(in srgb, var(--ts-c-teal) 25%, transparent);
+      font-size: 0.875rem;
+      color: var(--ts-ink-soft);
+      a {
+        font-weight: 600;
+        color: var(--ts-brand);
+      }
+    }
+    .ts-center-actions {
+      margin: 1rem 0 0;
+      font-size: 0.875rem;
+      a {
+        font-weight: 600;
+        color: var(--ts-brand);
+      }
+    }
     .ts-project-header {
       display: flex;
       align-items: flex-end;
@@ -138,6 +210,11 @@ export class ProjectShellPage {
   readonly key = input.required<string>();
 
   protected readonly facade = inject(ProjectFacade);
+  protected readonly auth = inject(AuthFacade);
+  private readonly router = inject(Router);
+  protected readonly publicTone = PUBLIC_TONE;
+  /** Where to come back after signing in. */
+  protected readonly url = () => this.router.url;
   protected readonly roleLabel = (role: keyof typeof ROLE) => ROLE[role];
   protected readonly tone = projectTone;
   protected readonly memberNames = computed(() =>