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/ports/find-issues.repository.ts

@@ -47,6 +47,8 @@ export abstract class FindIssuesRepository {
     filter: CrossProjectIssueFilter,
   ): Promise<Page<IssueReadModel>>;
   abstract stats(projectId: string): Promise<ProjectStatsReadModel>;
+  /** Open tickets (TODO, IN_PROGRESS or QA category) assigned to someone, in any project. */
+  abstract findOpenAssignedTo(userId: string): Promise<IssueReadModel[]>;
   /** Every ticket of a project (statistics). */
   abstract findByProject(projectId: string): Promise<IssueReadModel[]>;
   abstract releaseProgress(

libs/api/tracker/application/src/lib/ports/find-projects.repository.ts

@@ -8,4 +8,6 @@ export abstract class FindProjectsRepository {
     projectId: string,
     userId: string,
   ): Promise<ProjectRole | null>;
+  /** Projects anyone can read, by name. */
+  abstract findPublic(): Promise<ProjectReadModel[]>;
 }

libs/api/tracker/application/src/lib/ports/index.ts

@@ -16,3 +16,4 @@ export * from './user-directory';
 export * from './release-issues.repository';
 export * from './upsert-materialized-timeline.repository';
 export * from './find-timeline.repository';
+export * from './tracker-streams.repository';

libs/api/tracker/application/src/lib/ports/project-keys.repository.ts

@@ -2,4 +2,6 @@
 export abstract class ProjectKeysRepository {
   /** Throws BusinessRuleError if the key is already taken. */
   abstract reserve(key: string, projectId: string): Promise<void>;
+  /** Frees the key of a deleted project (only if still held by it). */
+  abstract release(key: string, projectId: string): Promise<void>;
 }

libs/api/tracker/application/src/lib/ports/tracker-streams.repository.ts

@@ -0,0 +1,13 @@
+/**
+ * Write-side lookups over the event store (the source of truth, unlike the
+ * eventually-consistent read model): which streams belong to a project or a
+ * ticket. The cascade saga uses them to delete everything that hangs off a
+ * deleted project.
+ */
+export abstract class TrackerStreamsRepository {
+  abstract issueIdsOfProject(projectId: string): Promise<string[]>;
+  abstract releaseIdsOfProject(projectId: string): Promise<string[]>;
+  abstract commentIdsOfIssue(issueId: string): Promise<string[]>;
+  /** Tickets that were ever linked to `issueId` (they may have unlinked since). */
+  abstract issueIdsLinkingTo(issueId: string): Promise<string[]>;
+}

libs/api/tracker/application/src/lib/ports/upsert-materialized-issue.repository.ts

@@ -25,6 +25,8 @@ export abstract class UpsertMaterializedIssueRepository {
     projectId: string,
     categories: Record<string, StatusCategory>,
   ): Promise<void>;
+  /** The ticket was deleted: its view, its timeline and the links shown on other tickets go. */
+  abstract remove(issueId: string): Promise<void>;
   /** Keeps the denormalised release name of every issue in sync. */
   abstract renameRelease(releaseId: string, name: string): Promise<void>;
 }

libs/api/tracker/application/src/lib/ports/upsert-materialized-project.repository.ts

@@ -6,4 +6,6 @@ export abstract class UpsertMaterializedProjectRepository {
     project: Pick<ProjectReadModel, 'id' | 'version'> &
       Partial<ProjectReadModel>,
   ): Promise<void>;
+  /** The project was deleted: its view, activity and timeline go. */
+  abstract remove(projectId: string): Promise<void>;
 }

libs/api/tracker/application/src/lib/ports/upsert-materialized-release.repository.ts

@@ -6,4 +6,5 @@ export abstract class UpsertMaterializedReleaseRepository {
     release: Pick<ReleaseReadModel, 'id' | 'version'> &
       Partial<ReleaseReadModel>,
   ): Promise<void>;
+  abstract remove(releaseId: string): Promise<void>;
 }