Add testimonials section and Q&A submit CTA; v1.0.8

- Testimonials: new Testimonial type, CMS field, admin UI under About,
  and TestimonialsSection rendered on homepage and About page (hidden when empty)
- Q&A: "Submit a Question →" CTA at bottom of Q&A page linking to /contact

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

src/content.ts

@@ -66,6 +66,13 @@ export interface PodcastFeaturedLink {
   discussionQuestions?: string[]
 }
 
+export interface Testimonial {
+  id: string
+  quote: string
+  name: string
+  source?: string
+}
+
 export interface FinishedBook {
   id: string
   title: string
@@ -247,6 +254,8 @@ export interface SiteContent {
   episodesSeoIntro: string
   // ── Finished Books ──
   finishedBooks: FinishedBook[]
+  // ── Testimonials ──
+  testimonials: Testimonial[]
 }
 
 export const DEFAULTS: SiteContent = {
@@ -447,6 +456,7 @@ export const DEFAULTS: SiteContent = {
   ],
   podcastFeaturedLinks: [],
   finishedBooks: [],
+  testimonials: [],
   episodesSeoIntro: 'Verse by Verse with Nate is an expository Bible teaching podcast where we go through Scripture one verse at a time. Each episode digs into the text carefully and practically, helping you understand what the Bible says, what it means, and how to live it out. New episodes released regularly — subscribe on Spotify or your favorite podcast platform.',
   seo: {
     title: 'Verse by Verse with Nate',