feat: conversations on a ticket are settled, and you see who is typing

A top-level comment and its replies can be resolved by whoever can
change the ticket (CommentThreadResolvedEvent), with an optional
conclusion added as a reply marked as a decision, so it shows above the
ticket. A settled conversation folds to one line (topic, who settled it
and the conclusion) and can be unfolded or reopened; the header counts
the open ones, and finishing the ticket with one open asks first.

«Ana está escribiendo…» shows in the conversation being answered, at
once: a `typing` mutation publishes to a Redis channel per ticket
(`typing` subscription), never stored. In replies, Enter sends and
Shift+Enter breaks the line, except inside lists and code.

API: resolveThread / PUT-DELETE /api/comments/{id}/resolution, Comment
.resolved/resolvedBy/resolvedAt, typing mutation and subscription. MCP:
resolve_thread.

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

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

@@ -13,6 +13,7 @@ import {
   ProjectChangeGql,
   ReleaseChangeGql,
   SprintChangeGql,
+  TypingGql,
 } from './types';
 
 const asIs = { resolve: <T>(payload: T) => payload };
@@ -48,6 +49,18 @@ export class SubscriptionResolver {
     return this.changes.watchComments(me.id, issueId);
   }
 
+  @Subscription(() => TypingGql, {
+    ...asIs,
+    description:
+      "Who is writing on a ticket, as they type (one's own come too: leave them out)",
+  })
+  typing(
+    @CurrentUser() me: User,
+    @Args('issueId', { type: () => ID }) issueId: string,
+  ) {
+    return this.changes.watchTyping(me.id, issueId);
+  }
+
   @Subscription(() => ActivityGql, {
     ...asIs,
     description: 'Live activity feed',