feat: formatted text, a list view, ticket details, public proposals and votes

Formatted text
- Descriptions, comments, replies and release notes render Markdown,
  sanitised with DOMPurify (tested against scripts, handlers and
  javascript: links). A pasted image is uploaded and written as
  ![name](attachment:<id>); the web fetches it with the reader's session,
  so it works on private projects. Every text box has a preview. The
  attachment upload now answers its attachmentId.

List view
- /p/:key/list: every ticket as rows, sortable by any column, filtered by
  text, open/closed, type, priority and assignee; status, priority and
  assignee change in place; bulk edit (the backlog's bar, now shared).

Ticket details
- Reactions on comments (GitHub's eight), for members and viewers.
- Duplicate a ticket: what it says, not where it stands.
- blockedBy: open tickets it waits for (BLOCKS / DEPENDS_ON), worked out
  when reading with one query per board or page; shown on cards, list
  rows and the ticket.

Public proposals
- A public project can take bug reports and ideas from anyone
  (acceptsProposals): POST /api/explore/projects/{project}/proposals and
  the form at /p/:key/proponer. They become tickets labelled «propuesta»,
  opened by TaskStream; a honeypot field and 5 per address every 15
  minutes keep spam out. No e-mail is asked: it would be public.

Votes
- Anyone signed in votes on a public project's tickets, members on a
  private one (voteIssue, PUT/DELETE /api/issues/{issue}/vote): votes and
  voted on each ticket, buttons on the ticket and the roadmap, a column
  in the list. The showcase carries votes and the open proposals.

MCP: vote_issue, duplicate_issue, react_to_comment; listings show
blockers and votes. Docs, Word and PDF updated; chat notifications
(Discord, Slack, Telegram) noted for later.

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

libs/api/tracker/application/src/lib/comments.service.ts

@@ -5,6 +5,7 @@ import { AddCommentCommand } from './commands/add-comment.command';
 import { CommandResult } from './commands/command-result';
 import { DeleteCommentCommand } from './commands/delete-comment.command';
 import { EditCommentCommand } from './commands/edit-comment.command';
+import { ReactToCommentCommand } from './commands/react-to-comment.command';
 import { Page } from './ports/find-issues.repository';
 import { GetCommentsQuery } from './queries/get-comments.query';
 
@@ -36,6 +37,18 @@ export class CommentsService {
     );
   }
 
+  /** Adds (`on`) or takes back one's reaction (👍…). */
+  react(
+    actorId: string,
+    commentId: string,
+    emoji: string,
+    on: boolean,
+  ): Promise<CommandResult> {
+    return this.commandBus.execute(
+      new ReactToCommentCommand(actorId, commentId, emoji, on),
+    );
+  }
+
   delete(actorId: string, commentId: string): Promise<CommandResult> {
     return this.commandBus.execute(
       new DeleteCommentCommand(actorId, commentId),