feat: CAPA overdue escalation cron — 4 thresholds, once-per-threshold via notifications_log

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FFDuBhMKvoWjrWT3ZnGmmr

tests/lib/notifications/capa-escalation.test.ts

@@ -0,0 +1,34 @@
+import { describe, it, expect } from 'vitest'
+import { getEscalationThreshold } from '@/lib/notifications/capa-escalation'
+
+describe('getEscalationThreshold', () => {
+  function daysFromNow(n: number): string {
+    const d = new Date()
+    d.setDate(d.getDate() + n)
+    return d.toISOString().split('T')[0]
+  }
+
+  it('returns warning_3d when due in 3 days', () => {
+    expect(getEscalationThreshold(daysFromNow(3))).toBe('warning_3d')
+  })
+
+  it('returns due_today when due today', () => {
+    expect(getEscalationThreshold(daysFromNow(0))).toBe('due_today')
+  })
+
+  it('returns overdue_3d when 3 days past due', () => {
+    expect(getEscalationThreshold(daysFromNow(-3))).toBe('overdue_3d')
+  })
+
+  it('returns overdue_7d when 7 days past due', () => {
+    expect(getEscalationThreshold(daysFromNow(-7))).toBe('overdue_7d')
+  })
+
+  it('returns null for 2 days before due (no threshold)', () => {
+    expect(getEscalationThreshold(daysFromNow(2))).toBeNull()
+  })
+
+  it('returns null for 4 days before due', () => {
+    expect(getEscalationThreshold(daysFromNow(4))).toBeNull()
+  })
+})