Refactor price calculation in MakerPointsEngine for improved accuracy

- Replaced direct price calculations with a new method `normalizeDepthTargetPrice` to ensure valid target prices for buy and sell orders.
- Updated all instances of price calculations in the MakerPointsEngine to utilize the new normalization method.
- Added boundary tests for `getDepthBetweenPrices` to validate behavior when prices are exactly at the target.

tests/price-depth-filter-boundary.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it } from "vitest";
+import { getDepthBetweenPrices } from "../src/utils/price";
+import type { AsterDepth } from "../src/exchanges/types";
+
+describe("getDepthBetweenPrices boundary", () => {
+  it("SELL side excludes quantity exactly at target price", () => {
+    const depth: AsterDepth = {
+      lastUpdateId: 1,
+      bids: [],
+      asks: [
+        ["69345", "1"],
+        ["69349", "2"],
+        ["69350", "999"],
+        ["69351", "3"],
+      ],
+    };
+
+    const total = getDepthBetweenPrices(depth, "SELL", 69350);
+    expect(total).toBe(3); // 仅 69345 + 69349
+  });
+
+  it("BUY side excludes quantity exactly at target price", () => {
+    const depth: AsterDepth = {
+      lastUpdateId: 1,
+     bids: [
+        ["69355", "1"],
+        ["69351", "2"],
+        ["69350", "999"],
+        ["69349", "3"],
+      ],
+      asks: [],
+    };
+
+    const total = getDepthBetweenPrices(depth, "BUY", 69350);
+    expect(total).toBe(3); // 仅 69355 + 69351
+  });
+});