feat: teams within a project

Projects keep teams of members in their settings (settings.teams; people
outside the project are dropped, teams are archived, not removed; absent
when saving means unchanged). Tickets go to a team (`team`, also filtered
in the list and in MCP search_issues), and a comment mentioning
@[Frontend](team-FRONT) tells each of its members. Settings has the teams
with their members, the ticket a «Equipo» select, the list a team filter,
and «@» offers the teams after the people.

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

apps/api/e2e/tracker.e2e-spec.ts

@@ -1641,4 +1641,63 @@ describe('task-stream (e2e)', () => {
       ).status,
     ).toBe(200);
   });
+
+  it('groups members in teams: tickets go to them and @team tells them', async () => {
+    const key = 'T' + Date.now().toString(36).slice(-5).toUpperCase();
+    await rest('token-ana', 'POST', '/projects', { key, name: key });
+    const project = await eventually(
+      () => rest('token-ana', 'GET', `/projects/${key}`),
+      (r) => r.status === 200,
+    );
+    await rest('token-ana', 'POST', `/projects/${key}/members`, {
+      userId: '102',
+    });
+    expect(
+      (
+        await rest('token-ana', 'PUT', `/projects/${key}/settings`, {
+          ...project.body['settings'],
+          teams: [
+            { id: 'FRONT', name: 'Frontend', memberIds: ['102', 'nobody'] },
+          ],
+        })
+      ).status,
+    ).toBe(200);
+    const settings = await eventually(
+      () => rest('token-ana', 'GET', `/projects/${key}`),
+      (r) => r.body['settings'].teams.length === 1,
+    );
+    expect(settings.body['settings'].teams[0].memberIds).toEqual(['102']);
+
+    const created = await rest('token-ana', 'POST', `/projects/${key}/issues`, {
+      type: 'TASK',
+      title: 'Para el equipo',
+      team: 'FRONT',
+    });
+    const ticket = created.body['key'];
+    await rest('token-ana', 'POST', `/projects/${key}/issues`, {
+      type: 'TASK',
+      title: 'Sin equipo',
+    });
+    const mine = await eventually(
+      () => rest('token-ana', 'GET', `/projects/${key}/issues?team=FRONT`),
+      (r) => r.body?.['total'] === 1,
+    );
+    expect(mine.body['items'][0]).toMatchObject({ key: ticket, team: 'FRONT' });
+
+    await rest('token-ana', 'POST', `/issues/${ticket}/comments`, {
+      body: '¿Lo miráis, @[Frontend](team-FRONT)?',
+    });
+    const told = await eventually(
+      () => rest('token-bob', 'GET', '/me/notifications'),
+      (r) =>
+        r.body?.items?.some(
+          (n: { kind: string; issueKey: string }) =>
+            n.kind === 'MENTIONED' && n.issueKey === ticket,
+        ),
+    );
+    expect(
+      told.body.items.find((n: { kind: string }) => n.kind === 'MENTIONED')
+        .summary,
+    ).toMatch(/tu equipo Frontend/);
+  });
 });