fix: decouple AI completion from history save failures and improve history API errors

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

app/api/history/[id]/route.ts

@@ -1,21 +1,32 @@
 import { NextResponse } from "next/server";
 import { getHistoryUsername } from "@/lib/history/request-user";
-import { deleteHistoryEntry } from "@/lib/history/server-store";
+import {
+  deleteHistoryEntry,
+  historyStoreErrorMessage,
+} from "@/lib/history/server-store";
 
 export async function DELETE(
   _req: Request,
   { params }: { params: Promise<{ id: string }> },
 ) {
-  const username = await getHistoryUsername();
-  if (!username) {
-    return NextResponse.json({ error: "请先登录" }, { status: 401 });
-  }
+  try {
+    const username = await getHistoryUsername();
+    if (!username) {
+      return NextResponse.json({ error: "请先登录" }, { status: 401 });
+    }
 
-  const { id } = await params;
-  const removed = await deleteHistoryEntry(username, id);
-  if (!removed) {
-    return NextResponse.json({ error: "记录不存在" }, { status: 404 });
-  }
+    const { id } = await params;
+    const removed = await deleteHistoryEntry(username, id);
+    if (!removed) {
+      return NextResponse.json({ error: "记录不存在" }, { status: 404 });
+    }
 
-  return NextResponse.json({ ok: true });
+    return NextResponse.json({ ok: true });
+  } catch (err) {
+    console.error("[history DELETE]", err);
+    return NextResponse.json(
+      { error: historyStoreErrorMessage(err) },
+      { status: 500 },
+    );
+  }
 }