feat: perf optimizations

- improved search_knowledgebase_tool
- Added new endpoint to batch-fetch comments for multiple messages, reducing the number of API calls.
- Introduced CommentBatchRequest and CommentBatchResponse schemas for handling batch requests and responses.
- Updated chat_comments_service to validate message existence and permissions before fetching comments.
- Enhanced frontend with useBatchCommentsPreload hook to optimize comment loading for assistant messages.

surfsense_web/hooks/use-comments.ts

@@ -1,4 +1,5 @@
-import { useQuery } from "@tanstack/react-query";
+import { useQuery, useQueryClient } from "@tanstack/react-query";
+import { useEffect, useRef } from "react";
 import { chatCommentsApiService } from "@/lib/apis/chat-comments-api.service";
 import { cacheKeys } from "@/lib/query-client/cache-keys";
 
@@ -7,12 +8,84 @@ interface UseCommentsOptions {
 	enabled?: boolean;
 }
 
+// ---------------------------------------------------------------------------
+// Module-level coordination: when a batch request is in-flight, individual
+// useComments queryFns piggy-back on it instead of making their own requests.
+// ---------------------------------------------------------------------------
+let _batchInflight: Promise<void> | null = null;
+let _batchTargetIds = new Set<number>();
+
 export function useComments({ messageId, enabled = true }: UseCommentsOptions) {
+	const queryClient = useQueryClient();
+
 	return useQuery({
 		queryKey: cacheKeys.comments.byMessage(messageId),
 		queryFn: async () => {
+			// Yield one macro-task so the batch prefetch useEffect (which sets
+			// _batchInflight) has a chance to fire before we decide to fetch.
+			await new Promise<void>((r) => setTimeout(r, 0));
+
+			if (_batchInflight && _batchTargetIds.has(messageId)) {
+				await _batchInflight;
+				const cached = queryClient.getQueryData(cacheKeys.comments.byMessage(messageId));
+				if (cached) return cached;
+			}
+
 			return chatCommentsApiService.getComments({ message_id: messageId });
 		},
 		enabled: enabled && !!messageId,
+		staleTime: 30_000,
 	});
 }
+
+/**
+ * Batch-fetch comments for all given message IDs in a single request, then
+ * seed the per-message React Query cache so individual useComments hooks
+ * resolve from cache instead of firing their own requests.
+ */
+export function useBatchCommentsPreload(messageIds: number[]) {
+	const queryClient = useQueryClient();
+	const prevKeyRef = useRef<string>("");
+
+	useEffect(() => {
+		if (!messageIds.length) return;
+
+		const key = messageIds
+			.slice()
+			.sort((a, b) => a - b)
+			.join(",");
+		if (key === prevKeyRef.current) return;
+		prevKeyRef.current = key;
+
+		_batchTargetIds = new Set(messageIds);
+		let cancelled = false;
+
+		const promise = chatCommentsApiService
+			.getBatchComments({ message_ids: messageIds })
+			.then((data) => {
+				if (cancelled) return;
+				for (const [msgIdStr, commentList] of Object.entries(data.comments_by_message)) {
+					queryClient.setQueryData(cacheKeys.comments.byMessage(Number(msgIdStr)), commentList);
+				}
+			})
+			.catch(() => {
+				// Batch failed; individual queryFns will fall through to their own fetch
+			})
+			.finally(() => {
+				if (_batchInflight === promise) {
+					_batchInflight = null;
+					_batchTargetIds = new Set();
+				}
+			});
+
+		_batchInflight = promise;
+
+		return () => {
+			cancelled = true;
+			if (_batchInflight === promise) {
+				_batchInflight = null;
+				_batchTargetIds = new Set();
+			}
+		};
+	}, [messageIds, queryClient]);
+}