fix: convert timestamp columns to Unix epoch seconds in candles and annotations API

src/app/api/annotations/route.ts

@@ -23,7 +23,12 @@ export async function GET(request: NextRequest) {
       .from(annotations)
       .where(eq(annotations.chart_id, parseInt(chartId, 10)));
 
-    return NextResponse.json(allAnnotations);
+    const normalized = allAnnotations.map((a) => ({
+      ...a,
+      timestamp: a.timestamp instanceof Date ? Math.floor(a.timestamp.getTime() / 1000) : a.timestamp,
+    }));
+
+    return NextResponse.json(normalized);
   } catch (error: any) {
     return NextResponse.json(
       { error: error.message || 'Failed to fetch annotations' },

src/app/api/candles/route.ts

@@ -29,7 +29,12 @@ export async function GET(request: NextRequest) {
       .where(eq(candles.chart_id, parseInt(chartId, 10)))
       .orderBy(asc(candles.time));
 
-    return NextResponse.json(allCandles);
+    const normalized = allCandles.map((c) => ({
+      ...c,
+      time: c.time instanceof Date ? Math.floor(c.time.getTime() / 1000) : c.time,
+    }));
+
+    return NextResponse.json(normalized);
   } catch (error: any) {
     return NextResponse.json(
       { error: error.message || 'Failed to fetch candles' },