feat(server): trigger workspace embedding (#12328)

fix AI-127

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

- **New Features**
  - Added automated event handling for workspace updates and document embedding, streamlining document embedding workflows.
  - Introduced detection and queuing of documents needing embedding, excluding ignored documents.
- **Improvements**
  - Enhanced performance of embedding-related searches by filtering results at the database level.
  - Increased concurrency for embedding job processing to improve throughput.
- **Bug Fixes**
  - Improved error handling and fallback for missing document titles during embedding.
  - Added safeguards to skip invalid embedding jobs based on document identifiers.
- **Tests**
  - Expanded test coverage for document embedding and ignored document filtering.
  - Updated end-to-end tests to use dynamic content for improved reliability.
  - Added synchronization waits in document creation utilities to improve test stability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

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

@@ -34,6 +34,33 @@ export class CopilotWorkspaceConfigModel extends BaseModel {
     });
   }
 
+  /**
+   * find docs to embed, excluding ignored and already embedded docs
+   * newer docs will be list first
+   * @param workspaceId id of the workspace
+   * @returns docIds
+   */
+  @Transactional()
+  async findDocsToEmbed(workspaceId: string): Promise<string[]> {
+    const docIds = await this.db.snapshot
+      .findMany({
+        where: {
+          workspaceId,
+          embedding: {
+            is: null,
+          },
+        },
+        select: { id: true },
+      })
+      .then(r => r.map(doc => doc.id));
+
+    const skipDocIds = await this.listIgnoredDocIds(workspaceId).then(
+      r => new Set(r.map(r => r.docId))
+    );
+
+    return docIds.filter(id => !skipDocIds.has(id));
+  }
+
   @Transactional()
   async updateIgnoredDocs(
     workspaceId: string,