feat(server): add comment-attachment model (#12909)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Introduced support for comment attachments, allowing users to add,
view, and manage attachments linked to comments within documents.
* **Tests**
* Added comprehensive tests to ensure correct behavior for adding,
updating, deleting, listing, and retrieving comment attachments.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->


#### PR Dependency Tree


* **PR #12909** 👈
  * **PR #12911**
    * **PR #12761**
      * **PR #12924**
        * **PR #12925**

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

packages/backend/server/src/models/__tests__/comment-attachment.spec.ts

@@ -0,0 +1,125 @@
+import test from 'ava';
+
+import { createModule } from '../../__tests__/create-module';
+import { Mockers } from '../../__tests__/mocks';
+import { Models } from '..';
+
+const module = await createModule();
+const models = module.get(Models);
+
+test.after.always(async () => {
+  await module.close();
+});
+
+test('should upsert comment attachment', async t => {
+  const workspace = await module.create(Mockers.Workspace);
+
+  // add
+  const item = await models.commentAttachment.upsert({
+    workspaceId: workspace.id,
+    docId: 'test-doc-id',
+    key: 'test-key',
+    name: 'test-name',
+    mime: 'text/plain',
+    size: 100,
+  });
+
+  t.is(item.workspaceId, workspace.id);
+  t.is(item.docId, 'test-doc-id');
+  t.is(item.key, 'test-key');
+  t.is(item.mime, 'text/plain');
+  t.is(item.size, 100);
+  t.truthy(item.createdAt);
+
+  // update
+  const item2 = await models.commentAttachment.upsert({
+    workspaceId: workspace.id,
+    docId: 'test-doc-id',
+    name: 'test-name',
+    key: 'test-key',
+    mime: 'text/html',
+    size: 200,
+  });
+
+  t.is(item2.workspaceId, workspace.id);
+  t.is(item2.docId, 'test-doc-id');
+  t.is(item2.key, 'test-key');
+  t.is(item2.mime, 'text/html');
+  t.is(item2.size, 200);
+
+  // make sure only one blob is created
+  const items = await models.commentAttachment.list(workspace.id);
+  t.is(items.length, 1);
+  t.deepEqual(items[0], item2);
+});
+
+test('should delete comment attachment', async t => {
+  const workspace = await module.create(Mockers.Workspace);
+  const item = await models.commentAttachment.upsert({
+    workspaceId: workspace.id,
+    docId: 'test-doc-id',
+    key: 'test-key',
+    name: 'test-name',
+    mime: 'text/plain',
+    size: 100,
+  });
+
+  await models.commentAttachment.delete(workspace.id, item.docId, item.key);
+
+  const item2 = await models.commentAttachment.get(
+    workspace.id,
+    item.docId,
+    item.key
+  );
+
+  t.is(item2, null);
+});
+
+test('should list comment attachments', async t => {
+  const workspace = await module.create(Mockers.Workspace);
+  const item1 = await models.commentAttachment.upsert({
+    workspaceId: workspace.id,
+    docId: 'test-doc-id',
+    name: 'test-name',
+    key: 'test-key',
+    mime: 'text/plain',
+    size: 100,
+  });
+
+  const item2 = await models.commentAttachment.upsert({
+    workspaceId: workspace.id,
+    docId: 'test-doc-id2',
+    name: 'test-name2',
+    key: 'test-key2',
+    mime: 'text/plain',
+    size: 200,
+  });
+
+  const items = await models.commentAttachment.list(workspace.id);
+
+  t.is(items.length, 2);
+  items.sort((a, b) => a.key.localeCompare(b.key));
+  t.is(items[0].key, item1.key);
+  t.is(items[1].key, item2.key);
+});
+
+test('should get comment attachment', async t => {
+  const workspace = await module.create(Mockers.Workspace);
+  const item = await models.commentAttachment.upsert({
+    workspaceId: workspace.id,
+    docId: 'test-doc-id',
+    name: 'test-name',
+    key: 'test-key',
+    mime: 'text/plain',
+    size: 100,
+  });
+
+  const item2 = await models.commentAttachment.get(
+    workspace.id,
+    item.docId,
+    item.key
+  );
+
+  t.truthy(item2);
+  t.is(item2?.key, item.key);
+});