feat: a dashboard for clients, behind a secret link

Owners and admins turn it on in Configuración → General, pick what it
shows (tickets per status, the sprint under way, release forecasts,
open epics and activity per day) and can renew or drop the link. Whoever
has it sees /share/{token} without an account: only those blocks, no
people nor single tickets but the epics, no links into the app, read
again every minute. A renewed or dropped link says it no longer works.

REST (GET/PUT/DELETE /api/projects/{project}/share and the public
GET /api/shared/dashboards/{token}) and GraphQL (dashboardShare,
shareDashboard, unshareDashboard, sharedDashboard). The token is kept
in dashboard_shares and goes with the project.

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

libs/api/tracker/presenters/src/lib/http/dto/requests.dto.ts

@@ -1526,3 +1526,22 @@ export class AddGitRepositoryDto {
   @MaxLength(40)
   name!: string;
 }
+
+export class ShareDashboardDto {
+  @ApiProperty({
+    type: [String],
+    example: ['flow', 'sprint', 'releases'],
+    description: 'Blocks to show: flow, sprint, releases, epics, activity',
+  })
+  @IsArray()
+  @ArrayMaxSize(10)
+  @IsString({ each: true })
+  blocks!: string[];
+
+  @ApiPropertyOptional({
+    description: 'A new secret: the old link stops working',
+  })
+  @IsOptional()
+  @IsBoolean()
+  renew?: boolean;
+}