feat(comments): implement comment resolution for the community build

Add comment resolve/re-open as a community feature, written from scratch on top
of the infrastructure already present in the community codebase: the
resolved_at/resolved_by_id columns, the COMMENT_RESOLVED notification job, the
resolveCommentMark collaboration handler, the commentResolved websocket event,
the comment service/types and the Open/Resolved tabs. No Enterprise-Edition code
is reused and there is no EE feature gating — resolving is available to anyone
who can comment.

Backend:
- add POST /comments/resolve (ResolveCommentDto) guarded by validateCanComment;
  reject resolving replies
- add CommentService.resolveComment: set/clear resolvedAt/resolvedById, sync the
  inline comment mark via collaboration handleYjsEvent, queue
  COMMENT_RESOLVED_NOTIFICATION (only when another user resolves), emit the
  commentResolved websocket event and write a resolve/reopen audit log

Frontend:
- add useResolveCommentMutation with optimistic update + rollback
- add ResolveComment toggle button
- wire the resolve button and menu item into comment-list-item / comment-menu,
  gated on canComment for parent comments

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/client/src/features/comment/components/comment-menu.tsx

@@ -1,18 +1,26 @@
 import { ActionIcon, Menu } from "@mantine/core";
-import { IconDots, IconEdit, IconTrash } from "@tabler/icons-react";
+import { IconDots, IconEdit, IconTrash, IconCircleCheck, IconCircleCheckFilled } from "@tabler/icons-react";
 import { modals } from "@mantine/modals";
 import { useTranslation } from "react-i18next";
 
 type CommentMenuProps = {
   onEditComment: () => void;
   onDeleteComment: () => void;
+  onResolveComment?: () => void;
   canEdit?: boolean;
+  canComment?: boolean;
+  isResolved?: boolean;
+  isParentComment?: boolean;
 };
 
 function CommentMenu({
   onEditComment,
   onDeleteComment,
+  onResolveComment,
   canEdit = true,
+  canComment = true,
+  isResolved = false,
+  isParentComment = false,
 }: CommentMenuProps) {
   const { t } = useTranslation();
 
@@ -47,6 +55,20 @@ function CommentMenu({
             {t("Edit comment")}
           </Menu.Item>
         )}
+        {isParentComment && canComment && (
+          <Menu.Item
+            onClick={onResolveComment}
+            leftSection={
+              isResolved ? (
+                <IconCircleCheckFilled size={14} />
+              ) : (
+                <IconCircleCheck size={14} />
+              )
+            }
+          >
+            {isResolved ? t("Re-open comment") : t("Resolve comment")}
+          </Menu.Item>
+        )}
         <Menu.Item
           leftSection={<IconTrash size={14} />}
           onClick={openDeleteModal}