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/http/dto/requests.dto.ts

@@ -389,6 +389,16 @@ export class MyIssuesQueryDto extends PageQueryDto {
   @IsBoolean()
   assignedToMe = true;
 
+  @ApiPropertyOptional({
+    type: Boolean,
+    description:
+      'Only the tickets I follow (with assignedToMe=false, whoever they are assigned to)',
+  })
+  @IsOptional()
+  @Transform(toBoolean)
+  @IsBoolean()
+  watching?: boolean;
+
   @ApiPropertyOptional({
     type: [String],
     description: 'Status ids. Repeat the parameter or separate with commas',
@@ -509,6 +519,15 @@ export class IssueSearchQueryDto extends PageQueryDto {
   @IsBoolean()
   noSprint?: boolean;
 
+  @ApiPropertyOptional({
+    type: Boolean,
+    description: 'Only the tickets I follow (none without a token)',
+  })
+  @IsOptional()
+  @Transform(toBoolean)
+  @IsBoolean()
+  watching?: boolean;
+
   @ApiPropertyOptional({
     format: 'date',
     description: 'Due on or after this day',