feat: notifications in the app and, optionally, by e-mail

Derived from events and kept per person: whoever a ticket is assigned to,
whoever reports or works on it when it moves, fails QA or gets a comment,
and whoever joins a project. Never about what you did yourself, once per
event. They arrive live through a subscription to a bell in the header,
and are copied by e-mail to whoever turns it on when SMTP_URL is set.

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

libs/web/tracker/domain/src/lib/models/enums.ts

@@ -38,3 +38,15 @@ export enum ReleaseStatus {
   RELEASED = 'RELEASED',
   ARCHIVED = 'ARCHIVED',
 }
+
+/** Why someone is told. */
+export enum NotificationKind {
+  ASSIGNED = 'ASSIGNED',
+  STATUS_CHANGED = 'STATUS_CHANGED',
+  QA_FAILED = 'QA_FAILED',
+  COMMENTED = 'COMMENTED',
+  MENTIONED = 'MENTIONED',
+  WATCHED = 'WATCHED',
+  ADDED_TO_PROJECT = 'ADDED_TO_PROJECT',
+  REMINDER = 'REMINDER',
+}

libs/web/tracker/domain/src/lib/models/models.ts

@@ -1,4 +1,5 @@
 import {
+  NotificationKind,
   IssueLinkType,
   IssuePriority,
   ProjectRole,
@@ -187,3 +188,25 @@ export interface CommandResult {
   key?: string | null;
   version: number;
 }
+
+/** Something the signed-in person should know. */
+export interface Notification {
+  id: string;
+  kind: NotificationKind;
+  projectId: string;
+  projectKey: string;
+  issueId: string | null;
+  issueKey: string | null;
+  actor: UserRef;
+  summary: string;
+  /** Null: unread. */
+  readAt: string | null;
+  createdAt: string;
+}
+
+export interface NotificationSettings {
+  /** Copies by e-mail. */
+  email: boolean;
+  /** Whether this installation can send e-mail at all. */
+  emailAvailable: boolean;
+}

libs/web/tracker/domain/src/lib/ports/gateways.ts

@@ -8,6 +8,8 @@ import {
   Issue,
   IssuePage,
   IssueSummary,
+  Notification,
+  NotificationSettings,
   Project,
   ProjectAnalytics,
   ProjectStats,
@@ -130,6 +132,18 @@ export abstract class UsersGateway {
   abstract search(term: string): Observable<UserDirectoryEntry[]>;
 }
 
+/** The signed-in person's notifications. */
+export abstract class NotificationsGateway {
+  abstract mine(
+    unreadOnly: boolean,
+    limit: number,
+  ): Observable<{ items: Notification[]; unread: number }>;
+  /** Without ids: all of them. */
+  abstract markRead(ids?: string[]): Observable<void>;
+  abstract settings(): Observable<NotificationSettings>;
+  abstract updateSettings(email: boolean): Observable<NotificationSettings>;
+}
+
 /** Realtime (GraphQL subscriptions over WebSocket). */
 export interface IssueChanged {
   action: string;
@@ -158,4 +172,5 @@ export abstract class TrackerRealtimeGateway {
   abstract releaseChanges(projectId: string): Observable<Release>;
   abstract projectChanges(projectId: string): Observable<ProjectChanged>;
   abstract myProjectsChanges(): Observable<ProjectChanged>;
+  abstract notifications(): Observable<Notification>;
 }