优化采样溢出处理，调整时间轴计算逻辑，确保在采样溢出时使用固定时间；更新显示信息以提示用户采样溢出情况

app/api/export/route.ts

@@ -57,6 +57,8 @@ export async function POST(req: NextRequest) {
         const dtMs = Number((r.rec_end_ms as bigint) - (r.rec_start_ms as bigint))
         if (Number.isFinite(dtMs) && dtMs > 0) stepMs = dtMs / r.sample_count
       }
+      // 采样溢出时强制 1ms 步长（与 16.384s/16384 对齐）
+      if (r.sample_count >= 16384) stepMs = 1
       const hasFit = r.fit_a != null
       for (let i = 0; i < r.code_data.length; i++) {
         const t = (i * stepMs).toFixed(3)

app/records/[id]/page.tsx

@@ -117,8 +117,10 @@ export default function Page({ params }: { params: Promise<{ id: string }> }) {
 
   const timeAxis = useMemo(() => {
     if (!rec) return [] as number[]
-    // 使用秒为单位，保留3位小数
+    // 使用秒为单位，保留3位小数；若采样溢出，固定为 16.384s
-    const step = rec.sampleCount > 0 ? rec.duration / rec.sampleCount : 0
+    const overflow = rec.sampleCount >= 16384
+    const effectiveDuration = overflow ? 16.384 : rec.duration
+    const step = rec.sampleCount > 0 ? effectiveDuration / rec.sampleCount : 0
     return Array.from({ length: rec.sampleCount }, (_, i) => +(i * step).toFixed(3))
   }, [rec])
 
@@ -198,7 +200,23 @@ export default function Page({ params }: { params: Promise<{ id: string }> }) {
               </div>
               <div className="rounded-lg border p-3 sm:p-4 dark:border-zinc-800">
                 <div className="text-sm text-zinc-500">采样</div>
-                <div className="mt-1 text-lg">{rec.sampleCount} 点 · {rec.duration.toFixed(3)} s · {(rec.sampleCount / rec.duration).toFixed(2)} Hz</div>
+                {(() => {
+                  const overflow = rec.sampleCount >= 16384
+                  const effectiveDuration = overflow ? 16.384 : rec.duration
+                  const hz = effectiveDuration > 0 ? (rec.sampleCount / effectiveDuration) : 0
+                  return (
+                    <div className="mt-1 text-lg">
+                      {rec.sampleCount} 点 ·{' '}
+                      <span
+                        className={overflow ? 'text-red-600 dark:text-red-400' : ''}
+                        title={overflow ? '采样溢出，时间将不准确' : undefined}
+                      >
+                        {effectiveDuration.toFixed(3)} s
+                      </span>
+                      {' '}· {hz.toFixed(2)} Hz
+                    </div>
+                  )
+                })()}
               </div>
               <div className="rounded-lg border p-3 sm:p-4 dark:border-zinc-800">
                 <div className="text-sm text-zinc-500">拟合</div>