fix(server): 修正档案成绩趋势图 y 轴坐标字符串拼接

apps/server/src/archive/archive-report.exam.spec.ts

@@ -0,0 +1,14 @@
+import { renderScoreTrendChart } from './archive-report.exam';
+
+describe('renderScoreTrendChart', () => {
+  it('places the first y-axis label 4px below the top gridline using numeric addition', () => {
+    const html = renderScoreTrendChart([
+      { examType: '文化', score: 60, examDate: '2026-01-01' },
+      { examType: '文化', score: 90, examDate: '2026-02-01' },
+      { examType: '文化', score: 70, examDate: '2026-03-01' },
+    ] as never);
+
+    expect(html).toContain('y="154.0"');
+    expect(html).not.toContain('y="150.04"');
+  });
+});

apps/server/src/archive/archive-report.exam.ts

@@ -146,7 +146,7 @@ export function renderScoreTrendChart(exams: ExamScore[]): string {
   for (let i = 0; i <= ySteps; i++) {
     const val = minScore + (scoreRange * i) / ySteps;
     const y = scaleY(val);
-    yLabels += `<text x="${pad.left - 6}" y="${y.toFixed(1) + 4}" text-anchor="end" fill="#667085" font-size="10">${val.toFixed(0)}</text>`;
+    yLabels += `<text x="${pad.left - 6}" y="${(y + 4).toFixed(1)}" text-anchor="end" fill="#667085" font-size="10">${val.toFixed(0)}</text>`;
     if (i > 0) {
       yLabels += `<line x1="${pad.left}" y1="${y.toFixed(1)}" x2="${w - pad.right}" y2="${y.toFixed(1)}" stroke="#eaf3fd" stroke-width="1"/>`;
     }