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/issues.service.ts

@@ -8,8 +8,11 @@ import {
   IssueReadModel,
 } from '@task-stream/api/tracker/domain';
 import { AssignIssueCommand } from './commands/assign-issue.command';
+import { DuplicateIssueCommand } from './commands/duplicate-issue.command';
+import { VoteIssueCommand } from './commands/vote-issue.command';
 import {
   AttachFileCommand,
+  AttachmentResult,
   IncomingFile,
 } from './commands/attach-file.command';
 import { DetachFileCommand } from './commands/detach-file.command';
@@ -169,7 +172,7 @@ export class IssuesService {
     issueId: string,
     file: IncomingFile,
     commentId: string | null = null,
-  ): Promise<CommandResult> {
+  ): Promise<AttachmentResult> {
     return this.commandBus.execute(
       new AttachFileCommand(actorId, issueId, file, commentId),
     );
@@ -258,6 +261,16 @@ export class IssuesService {
     return this.commandBus.execute(new RestoreIssueCommand(actorId, issueId));
   }
 
+  /** Votes for the ticket (`on`) or takes the vote back. */
+  vote(actorId: string, issueId: string, on: boolean): Promise<CommandResult> {
+    return this.commandBus.execute(new VoteIssueCommand(actorId, issueId, on));
+  }
+
+  /** A new ticket like this one (what it says, not where it stands). */
+  duplicate(actorId: string, issueId: string): Promise<CommandResult> {
+    return this.commandBus.execute(new DuplicateIssueCommand(actorId, issueId));
+  }
+
   trashed(
     viewerId: string | null,
     projectId: string,