feat(小宝预警): 自动生成 AI 风险解读

apps/web/lib/xiaobao-risk-ai.test.ts

@@ -5,6 +5,7 @@ import type { XiaobaoRiskSnapshot } from './xiaobao-risk-trend';
 import {
   buildRiskInsightSignature,
   buildRiskInterpretRequest,
+  findPreviousRiskSnapshot,
   shouldRequestRiskInsight,
 } from './xiaobao-risk-ai';
 
@@ -243,3 +244,18 @@ test('buildRiskInterpretRequest compresses frontend risk evidence for the backen
   assert.deepEqual(payload.dailyEvidence.needsProgressItems, ['Backend task has no update.']);
   assert.equal(payload.silentRisks[0].detail, 'No update for 5 days.');
 });
+
+test('findPreviousRiskSnapshot returns latest snapshot before today for the version', () => {
+  const previous = findPreviousRiskSnapshot(
+    [
+      snapshot({ versionId: 'ver-1', date: '2026-06-29', riskScore: 70, createdAt: '2026-06-29T10:00:00.000Z' }),
+      snapshot({ versionId: 'ver-1', date: '2026-06-28', riskScore: 52, createdAt: '2026-06-28T10:00:00.000Z' }),
+      snapshot({ versionId: 'ver-1', date: '2026-06-27', riskScore: 38, createdAt: '2026-06-27T10:00:00.000Z' }),
+      snapshot({ versionId: 'ver-2', date: '2026-06-28', riskScore: 90, createdAt: '2026-06-28T11:00:00.000Z' }),
+    ],
+    'ver-1',
+    '2026-06-29',
+  );
+
+  assert.equal(previous?.riskScore, 52);
+});

apps/web/lib/xiaobao-risk-ai.ts

@@ -102,6 +102,16 @@ export function getReusableInsight(
   return findCachedInsight(cache, risk.versionId, buildRiskInsightSignature(risk));
 }
 
+export function findPreviousRiskSnapshot(
+  snapshots: XiaobaoRiskSnapshot[],
+  versionId: string,
+  today: string,
+): XiaobaoRiskSnapshot | undefined {
+  return snapshots
+    .filter((snapshot) => snapshot.versionId === versionId && snapshot.date < today)
+    .sort((a, b) => b.createdAt.localeCompare(a.createdAt))[0];
+}
+
 export function buildRiskInterpretRequest(risk: XiaobaoVersionRisk): AgentRiskInterpretRequest {
   return {
     versionId: risk.versionId,