Use lunar calendar input for birth date with solar conversion display.

Add LunarBirthPicker for bazi and combined forms, converting lunar input to solar for chart calculation.

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

components/modes/bazi-form.tsx

@@ -8,7 +8,9 @@ import { ZenCard } from "@/components/ui/zen-card";
 import { ModeWorkspace } from "@/components/layout/mode-workspace";
 import ResultAI from "@/components/result-ai";
 import BaziChartDisplay from "@/components/modes/bazi-chart";
-import DateTimePicker, { nowDateString } from "@/components/shared/datetime-picker";
+import LunarBirthPicker, {
+  todaySolarYmd,
+} from "@/components/shared/lunar-birth-picker";
 import RegionSelect, {
   useRegionLocation,
 } from "@/components/shared/region-select";
@@ -16,7 +18,7 @@ import { calculateBazi, type BaziChart } from "@/lib/calc/bazi";
 import { streamAiCompletion } from "@/lib/ai/client-stream";
 
 export default function BaziForm() {
-  const [date, setDate] = useState(nowDateString());
+  const [date, setDate] = useState(todaySolarYmd());
   const [time, setTime] = useState("12:00");
   const [unknownHour, setUnknownHour] = useState(false);
   const [gender, setGender] = useState<"male" | "female">("male");
@@ -110,12 +112,12 @@ export default function BaziForm() {
       }
     >
       <ZenCard title="出生 · 命局" subtitle="四柱排盘所需信息" className="flex h-full min-h-0 flex-col">
-        <DateTimePicker
+        <LunarBirthPicker
           label="出生日期 / 时间"
-          date={date}
+          solarDate={date}
           time={time}
           timeDisabled={unknownHour}
-          onDateChange={setDate}
+          onSolarDateChange={setDate}
           onTimeChange={setTime}
         />
         <label className="flex items-center gap-2 text-xs text-muted-foreground">