fix(server): missing embedding search (#13401)

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

* **New Features**
* Enhanced search functionality to include results from additional
"blob" data sources, providing more comprehensive search results.

* **Bug Fixes**
* Improved messaging to ensure "No results found" is only shown when no
relevant results exist across all data sources.

* **Tests**
* Updated test cases to reflect new keyword contexts, improving
validation accuracy for search-related features.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/copilot/context/service.ts

@@ -232,7 +232,7 @@ export class CopilotContextService implements OnApplicationBootstrap {
     const embedding = await this.embeddingClient.getEmbedding(content, signal);
     if (!embedding) return [];
 
-    const [fileChunks, workspaceChunks, scopedWorkspaceChunks] =
+    const [fileChunks, blobChunks, workspaceChunks, scopedWorkspaceChunks] =
       await Promise.all([
         this.models.copilotWorkspace.matchFileEmbedding(
           workspaceId,
@@ -240,6 +240,12 @@ export class CopilotContextService implements OnApplicationBootstrap {
           topK * 2,
           threshold
         ),
+        this.models.copilotWorkspace.matchBlobEmbedding(
+          workspaceId,
+          embedding,
+          topK * 2,
+          threshold
+        ),
         this.models.copilotContext.matchWorkspaceEmbedding(
           embedding,
           workspaceId,
@@ -259,6 +265,7 @@ export class CopilotContextService implements OnApplicationBootstrap {
 
     if (
       !fileChunks.length &&
+      !blobChunks.length &&
       !workspaceChunks.length &&
       !scopedWorkspaceChunks?.length
     ) {
@@ -267,7 +274,12 @@ export class CopilotContextService implements OnApplicationBootstrap {
 
     return await this.embeddingClient.reRank(
       content,
-      [...fileChunks, ...workspaceChunks, ...(scopedWorkspaceChunks || [])],
+      [
+        ...fileChunks,
+        ...blobChunks,
+        ...workspaceChunks,
+        ...(scopedWorkspaceChunks || []),
+      ],
       topK,
       signal
     );