feat(server): skip embedding for deprecated doc ids & empty docs (#13211)

fix AI-367

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

* **Bug Fixes**
* Improved document filtering to exclude settings documents and empty
blobs from embedding and status calculations.
* Enhanced embedding jobs to skip processing deprecated documents if a
newer version exists, ensuring only up-to-date documents are embedded.
* **New Features**
* Added a mutation to trigger the cron job for generating missing
titles.
* **Tests**
* Added test to verify exclusion of documents with empty content from
embedding.
* Updated embedding-related tests to toggle embedding state during
attachment upload under simulated network conditions.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/models/copilot-workspace.ts

@@ -58,10 +58,12 @@ export class CopilotWorkspaceConfigModel extends BaseModel {
             ON id.workspace_id = s.workspace_id
                AND id.doc_id = s.guid
         WHERE s.workspace_id = ${workspaceId}
-          AND s.guid != s.workspace_id
+          AND s.guid <> s.workspace_id
           AND s.guid NOT LIKE '%$%'
+          AND s.guid NOT LIKE '%:settings:%'
           AND e.doc_id IS NULL
-          AND id.doc_id IS NULL;`;
+          AND id.doc_id IS NULL
+          AND s.blob <> E'\\\\x0000';`;
 
     return docIds.map(r => r.id);
   }
@@ -160,6 +162,8 @@ export class CopilotWorkspaceConfigModel extends BaseModel {
         { id: { notIn: ignoredDocIds } },
         { id: { not: workspaceId } },
         { id: { not: { contains: '$' } } },
+        { id: { not: { contains: ':settings:' } } },
+        { blob: { not: new Uint8Array([0, 0]) } },
       ],
     };