fix(frontend): no half-finished citations, correct state when SSE ends

Citations:
- In shouldShowCitationLoading, treat any unreplaced [cite-N] in cleanContent
  as show-loading (no body). Fixes Ultra and other modes when refs arrive
  before the <citations> block in the stream.
- Single rule: hasUnreplacedCitationRefs(cleanContent) => true forces loading;
  then isLoading && hasCitationsBlock(rawContent) for streaming indicator.

SSE end state:
- When stream finishes, SDK may set isLoading=false before client state has
  the final message content, so UI stayed wrong until refresh.
- Store onFinish(state) as finalState in chat page; clear when stream starts.
- Pass messagesOverride={finalState.messages} to MessageList when not loading
  so the list uses server-complete messages right after SSE ends (no refresh).

Chore:
- Stop tracking .githooks/pre-commit; add .githooks/ to .gitignore (local only).

Co-authored-by: Cursor <cursoragent@cursor.com>

---
fix(前端): 杜绝半成品引用，SSE 结束时展示正确状态

引用：
- shouldShowCitationLoading 中只要 cleanContent 仍含未替换的 [cite-N] 就
  只显示加载、不渲染正文，解决流式时引用块未到就出现 [cite-1] 的问题。
- 规则：hasUnreplacedCitationRefs(cleanContent) 为真则一律显示加载；
  此外 isLoading && hasCitationsBlock 用于流式时显示「正在整理引用」。

SSE 结束状态：
- 流结束时 SDK 可能先置 isLoading=false，客户端 messages 尚未包含
  最终内容，导致需刷新才显示正确。
- 在对话页保存 onFinish(state) 为 finalState，流开始时清空。
- 非加载时向 MessageList 传入 messagesOverride={finalState.messages}，
  列表在 SSE 结束后立即用服务端完整消息渲染，无需刷新。

杂项：
- 取消跟踪 .githooks/pre-commit，.gitignore 增加 .githooks/（仅本地）。

frontend/src/core/citations/utils.ts

@@ -205,18 +205,16 @@ export function hasUnreplacedCitationRefs(cleanContent: string): boolean {
 /**
  * Single source of truth: true when body must not be rendered (show loading instead).
  * Use after parseCitations: pass raw content, parsed cleanContent, and isLoading.
- * When streaming and any citation block is present, show loading so the indicator
- * is visible in all modes (Pro/Ultra often receive complete blocks in one chunk).
+ * Never show body when cleanContent still has [cite-N] (e.g. refs arrived before
+ * <citations> block in stream); also show loading while streaming with citation block.
  */
 export function shouldShowCitationLoading(
   rawContent: string,
   cleanContent: string,
   isLoading: boolean,
 ): boolean {
-  return (
-    (isLoading && hasCitationsBlock(rawContent)) ||
-    (hasCitationsBlock(rawContent) && hasUnreplacedCitationRefs(cleanContent))
-  );
+  if (hasUnreplacedCitationRefs(cleanContent)) return true;
+  return isLoading && hasCitationsBlock(rawContent);
 }
 
 /**