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

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

components/modes/liuyao-form.tsx

@@ -17,7 +17,7 @@ import RegionSelect, {
   useRegionLocation,
 } from "@/components/shared/region-select";
 import { streamAiCompletion } from "@/lib/ai/client-stream";
-import { saveHistoryEntry } from "@/lib/history/storage";
+import { saveHistoryEntrySafe } from "@/lib/history/storage";
 import type { GuaResult } from "@/lib/calc/hexagram";
 import todayJson from "@/lib/data/today.json";
 
@@ -34,6 +34,7 @@ export default function LiuyaoForm() {
   const [guaData, setGuaData] = useState<GuaResult | null>(null);
   const [completion, setCompletion] = useState("");
   const [error, setError] = useState("");
+  const [warning, setWarning] = useState("");
   const [isLoading, setIsLoading] = useState(false);
 
   const location = useRegionLocation(provinceCode, cityCode);
@@ -65,6 +66,7 @@ export default function LiuyaoForm() {
     }
 
     setError("");
+    setWarning("");
     setCompletion("");
     setIsLoading(true);
 
@@ -86,7 +88,7 @@ export default function LiuyaoForm() {
         },
         setCompletion,
       );
-      await saveHistoryEntry({
+      const saveResult = await saveHistoryEntrySafe({
         mode: "liuyao",
         title: guaData!.result.guaTitle,
         question,
@@ -104,6 +106,9 @@ export default function LiuyaoForm() {
           卦象: guaData!.result.guaTitle,
         },
       });
+      if (!saveResult.ok) {
+        setWarning(saveResult.error);
+      }
     } catch (e) {
       setError(e instanceof Error ? e.message : String(e));
     } finally {
@@ -122,6 +127,7 @@ export default function LiuyaoForm() {
     setGuaData(null);
     setCompletion("");
     setError("");
+    setWarning("");
     setIsLoading(false);
   }
 
@@ -129,6 +135,7 @@ export default function LiuyaoForm() {
     setGuaData(data);
     setCompletion("");
     setError("");
+    setWarning("");
   }
 
   const downloadPreamble =
@@ -145,6 +152,7 @@ export default function LiuyaoForm() {
           isLoading={isLoading}
           onCompletion={handleAnalyze}
           error={error}
+          warning={warning}
           emptyHint="完成起卦后，点击「AI 解读」"
           downloadFilename={
             completion && guaData