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>

apps/mcp/src/app/api/taskstream.schema.ts

@@ -3933,6 +3933,8 @@ export interface operations {
                 offset?: number;
                 /** @description true: tickets assigned to me. false: any ticket of my projects (e.g. ?assignedToMe=false&category=QA) */
                 assignedToMe?: boolean;
+                /** @description Only the tickets I follow (with assignedToMe=false, whoever they are assigned to) */
+                watching?: boolean;
                 /** @description Status ids. Repeat the parameter or separate with commas */
                 status?: string[];
                 /** @description Whatever each project calls its statuses */
@@ -4017,6 +4019,8 @@ export interface operations {
                 sprintId?: string;
                 /** @description Only tickets in no sprint */
                 noSprint?: boolean;
+                /** @description Only the tickets I follow (none without a token) */
+                watching?: boolean;
                 /** @description Due on or after this day */
                 dueFrom?: string;
                 /** @description Due on or before this day */