Make re-engagement email tiers configurable from admin; v1.1.20

Day thresholds and per-tier subject/body/CTA are now editable in the
Email Templates panel. Tier keys are position-based (t1/t2/t3) so
changing day values never re-sends emails already fired.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/content.ts

@@ -231,6 +231,17 @@ export interface SiteContent {
   studyReminderEmailBody: string
   studyReminderEmailCtaLabel: string
   studyReminderEmailSignoff: string
+  // ── Study Re-engagement Emails ──
+  studyReengagementDays: string
+  studyReengagementT1Subject: string
+  studyReengagementT1Body: string
+  studyReengagementT1Cta: string
+  studyReengagementT2Subject: string
+  studyReengagementT2Body: string
+  studyReengagementT2Cta: string
+  studyReengagementT3Subject: string
+  studyReengagementT3Body: string
+  studyReengagementT3Cta: string
   // ── Email Change Confirmation ──
   emailChangeSubject: string
   emailChangeBody: string
@@ -429,6 +440,16 @@ export const DEFAULTS: SiteContent = {
   studyReminderEmailBody: 'A new lesson has been unlocked in your study track. Open it below to continue where you left off.',
   studyReminderEmailCtaLabel: 'Open the Lesson',
   studyReminderEmailSignoff: 'Grace and peace,\nVerse by Verse with Nate',
+  studyReengagementDays: '7,14,30',
+  studyReengagementT1Subject: 'Your study is waiting for you',
+  studyReengagementT1Body: "It's been a while — your progress is saved and your next lesson is ready whenever you are.",
+  studyReengagementT1Cta: 'Continue Studying',
+  studyReengagementT2Subject: "Don't lose your momentum",
+  studyReengagementT2Body: "Every note and completed lesson is still right there. A little each day adds up — come back and continue.",
+  studyReengagementT2Cta: 'Return to Your Study',
+  studyReengagementT3Subject: 'Your progress is still here',
+  studyReengagementT3Body: "Your study progress is still intact and waiting. There's no deadline — come back whenever you're ready.",
+  studyReengagementT3Cta: 'Open Your Study',
   emailChangeSubject: 'Confirm your new email address',
   emailChangeBody: 'Click the link below to confirm your new account email. If you did not request this change, ignore this message.',
   emailChangeCtaLabel: 'Confirm Email Change',