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/server/src/core/comment/comment.controller.ts

@@ -8,10 +8,12 @@ import {
   Inject,
   NotFoundException,
   ForbiddenException,
+  BadRequestException,
 } from '@nestjs/common';
 import { CommentService } from './comment.service';
 import { CreateCommentDto } from './dto/create-comment.dto';
 import { UpdateCommentDto } from './dto/update-comment.dto';
+import { ResolveCommentDto } from './dto/resolve-comment.dto';
 import { PageIdDto, CommentIdDto } from './dto/comments.input';
 import { AuthUser } from '../../common/decorators/auth-user.decorator';
 import { AuthWorkspace } from '../../common/decorators/auth-workspace.decorator';
@@ -139,6 +141,54 @@ export class CommentController {
     return this.commentService.update(comment, dto, user);
   }
 
+  @HttpCode(HttpStatus.OK)
+  @Post('resolve')
+  async resolve(
+    @Body() dto: ResolveCommentDto,
+    @AuthUser() user: User,
+    @AuthWorkspace() workspace: Workspace,
+  ) {
+    const comment = await this.commentRepo.findById(dto.commentId, {
+      includeCreator: true,
+      includeResolvedBy: true,
+    });
+    if (!comment) {
+      throw new NotFoundException('Comment not found');
+    }
+
+    // Only top-level comments can be resolved; replies follow their parent.
+    if (comment.parentCommentId) {
+      throw new BadRequestException('Only parent comments can be resolved');
+    }
+
+    const page = await this.pageRepo.findById(comment.pageId);
+    if (!page) {
+      throw new NotFoundException('Page not found');
+    }
+
+    await this.pageAccessService.validateCanComment(page, user, workspace.id);
+
+    const updated = await this.commentService.resolveComment(
+      comment,
+      dto.resolved,
+      user,
+    );
+
+    this.auditService.log({
+      event: dto.resolved
+        ? AuditEvent.COMMENT_RESOLVED
+        : AuditEvent.COMMENT_REOPENED,
+      resourceType: AuditResource.COMMENT,
+      resourceId: comment.id,
+      spaceId: comment.spaceId,
+      metadata: {
+        pageId: comment.pageId,
+      },
+    });
+
+    return updated;
+  }
+
   @HttpCode(HttpStatus.OK)
   @Post('delete')
   async delete(@Body() input: CommentIdDto, @AuthUser() user: User, @AuthWorkspace() workspace: Workspace) {