feat: tickets I follow, and more news for followers

"Que sigo" on the home page lists the open tickets I follow, whoever
works on them; `watching` filters my issues (REST, GraphQL, MCP) and a
project's search (none without a session).

Followers now also hear when a ticket's priority or due date changes,
and when it enters or leaves a sprint. Smaller edits (title, labels…)
still do not notify.

Docs (with the REPLIED row the replies change missed), Word and PDF
updated.

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

libs/api/tracker/presenters/src/lib/graphql/issue.resolver.ts

@@ -98,6 +98,11 @@ export class IssueResolver {
   myIssues(
     @CurrentUser() me: User,
     @Args('assignedToMe', { defaultValue: true }) assignedToMe: boolean,
+    @Args('watching', {
+      defaultValue: false,
+      description: 'Only the tickets I follow',
+    })
+    watching: boolean,
     @Args('statuses', { type: () => [String], nullable: true })
     statuses: string[] | undefined,
     @Args('categories', { type: () => [StatusCategory], nullable: true })
@@ -113,6 +118,7 @@ export class IssueResolver {
   ) {
     return this.issuesService.mine(me.id, {
       assignedToMe,
+      watching,
       statuses: statuses ?? undefined,
       categories: categories ?? undefined,
       search: search ?? undefined,