refactor: centralize provider projections

src/modules/investments/instruments/infrastructure/tbank-candle.mapper.ts

@@ -0,0 +1,18 @@
+import type { TbankCandle } from '../../../../integrations/tbank/tbank.api';
+import type { SavedCandle } from '../domain/candle-coverage';
+
+import { formatDecimal } from '../../../../common/decimal';
+import { decimal } from '../../../../integrations/tbank/decimal';
+import { timestamp } from '../application/instrument-market';
+
+function toSavedCandle(candle: TbankCandle): SavedCandle {
+  const time = timestamp(candle.time);
+  if (!time || !candle.close) throw new Error('Invalid candle response');
+  return {
+    time,
+    close: formatDecimal(decimal(candle.close)),
+    isComplete: candle.isComplete === true,
+  };
+}
+
+export { toSavedCandle };