fix: add keyword index for type field to fix Qdrant codebase_search error

Fixes #8963

The codebase_search tool was failing with a "Index required but not found for type"
error when using Qdrant. This was because the search() method filters by the type
field to exclude metadata points, but no keyword index was created for this field.

Added creation of a keyword index for the type field in the _createPayloadIndexes()
method to enable proper filtering of metadata points during search operations.

Author: roomote

src/services/code-index/vector-store/qdrant-client.ts

@@ -296,6 +296,23 @@ export class QdrantVectorStore implements IVectorStore {
 	 * Creates payload indexes for the collection, handling errors gracefully.
 	 */
 	private async _createPayloadIndexes(): Promise<void> {
+		// Create index for the 'type' field to enable metadata filtering
+		try {
+			await this.client.createPayloadIndex(this.collectionName, {
+				field_name: "type",
+				field_schema: "keyword",
+			})
+		} catch (indexError: any) {
+			const errorMessage = (indexError?.message || "").toLowerCase()
+			if (!errorMessage.includes("already exists")) {
+				console.warn(
+					`[QdrantVectorStore] Could not create payload index for type on ${this.collectionName}. Details:`,
+					indexError?.message || indexError,
+				)
+			}
+		}
+
+		// Create indexes for pathSegments fields
 		for (let i = 0; i <= 4; i++) {
 			try {
 				await this.client.createPayloadIndex(this.collectionName, {