feat: comments marked as decisions, on top of the ticket and searchable

Whoever can change the ticket flags a comment as a decision (new event
CommentDecisionMarkedEvent on the comment). The ticket page lists its
decisions above the description, with a link to the comment in the
conversation (`?comment=<id>` scrolls to it and points at it), and the
search palette finds them by their text across my projects.

API: markDecision / PUT-DELETE /api/comments/{id}/decision; Issue.decisions
and GET /api/issues/{issue}/decisions; decisions(projectId?, search) and
GET /api/projects/{project}/decisions, GET /api/me/decisions. MCP:
mark_decision, search_decisions, and get_issue includes them.

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

apps/mcp/src/app/tools/issues.resolver.ts

@@ -254,7 +254,7 @@ export class IssuesResolver {
   @Tool({
     name: 'get_issue',
     description:
-      'A ticket in full: description, parent, checklist (with item ids), links, commits and pull requests, followers, allowed next statuses, and optionally its comments and history.',
+      'A ticket in full: description, parent, checklist (with item ids), links, commits and pull requests, followers, allowed next statuses, the comments marked as decisions, and optionally its comments and history.',
     paramsSchema: z.object({
       issue: issueRef,
       withComments: z.boolean().default(true),
@@ -289,8 +289,20 @@ export class IssuesResolver {
               emoji: r.emoji,
               by: r.users.map((u) => u.name),
             })),
+            decision: c.decision || undefined,
           }))
         : undefined;
+      const decisions = (
+        await this.api.data(
+          client.GET('/api/issues/{issue}/decisions', { params: { path } }),
+        )
+      ).map((c) => ({
+        commentId: c.id,
+        by: c.author.name,
+        at: c.createdAt,
+        markedBy: c.decidedBy?.name ?? null,
+        body: c.body,
+      }));
       const history = params.withHistory
         ? (
             await this.api.data(
@@ -322,6 +334,7 @@ export class IssuesResolver {
         attachments: issue.attachments.length,
         trashedAt: issue.trashedAt,
         createdAt: issue.createdAt,
+        decisions,
         comments,
         history,
       };
@@ -734,6 +747,67 @@ export class IssuesResolver {
     );
   }
 
+  @Tool({
+    name: 'mark_decision',
+    description:
+      'Mark a comment as a decision of its ticket (what was agreed), or unmark it (on: false). Whoever can change the ticket. Comment ids come with get_issue.',
+    paramsSchema: z.object({
+      commentId: z.string().min(1),
+      on: z.boolean().default(true),
+    }),
+    annotations: { ...WRITE, idempotentHint: true },
+  })
+  markDecision(
+    { commentId, on }: { commentId: string; on: boolean },
+    ctx: McpContext,
+  ) {
+    const client = this.api.as(ctx);
+    const options = { params: { path: { commentId } } };
+    return toolResult(() =>
+      this.api.data(
+        on
+          ? client.PUT('/api/comments/{commentId}/decision', options)
+          : client.DELETE('/api/comments/{commentId}/decision', options),
+      ),
+    );
+  }
+
+  @Tool({
+    name: 'search_decisions',
+    description:
+      'What was decided, by words in the decision: comments marked as decisions, most recent first, with their ticket. Of one project, or of all my projects without one.',
+    paramsSchema: z.object({
+      project: projectRef.optional(),
+      search: z.string().max(200).optional(),
+      limit: limit(100, 20),
+    }),
+    annotations: READ,
+  })
+  searchDecisions(
+    params: { project?: string; search?: string; limit: number },
+    ctx: McpContext,
+  ) {
+    return toolResult(async () => {
+      const client = this.api.as(ctx);
+      const query = { search: params.search, limit: params.limit };
+      const found = await this.api.data(
+        params.project
+          ? client.GET('/api/projects/{project}/decisions', {
+              params: { path: { project: params.project }, query },
+            })
+          : client.GET('/api/me/decisions', { params: { query } }),
+      );
+      return found.map((d) => ({
+        issue: d.issue.key,
+        title: d.issue.title,
+        commentId: d.comment.id,
+        by: d.comment.author.name,
+        at: d.comment.createdAt,
+        body: d.comment.body,
+      }));
+    });
+  }
+
   @Tool({
     name: 'vote_issue',
     description: