content: replace fake testimonial fallback with honest early-adopter CTA (#847)

The env-gated fallback branch previously showed fabricated testimonials
from Sarah K., Marcus T., and Jamie R. — people who don't exist. This is
a trust/integrity problem for a product that sells social proof.

When PUBLIC_MARKETING_WIDGET_ID is not set (current production state),
visitors now see an honest 'be one of our first featured customers' CTA
instead of invented quotes.

The real widget branch is preserved and will auto-activate once the env
var is configured in Cloudflare Pages.

Closes #847 (to be filed)

Co-authored-by: Mark from SocialProof <mark@socialproof.dev>

Author: proof-marketing[bot]

apps/marketing-site/src/pages/index.astro

@@ -186,9 +186,9 @@ const marketingWidgetScript = 'https://widget.socialproof.dev/v1/widget.js';
   <!-- SOCIAL PROOF SECTION — dogfood the product on our own marketing site when a widget is configured -->
   <section style="padding:72px 0;">
     <div class="container" style="text-align:center;">
-      <p class="section-label">What early users say</p>
-      <h2 class="section-title">Real businesses. Real results.</h2>
-      <p class="section-sub">From coaches to photographers to restaurant owners — here's what happened when they started sharing their collection link.</p>
+      <p class="section-label">Built in public — no fake social proof</p>
+      <h2 class="section-title">Real testimonials, coming soon.</h2>
+      <p class="section-sub">When our early users collect real testimonials, they'll appear right here — collected and displayed by SocialProof itself.</p>
       {marketingWidgetId ? (
         <>
           <div style="max-width:960px;margin:48px auto 0;text-align:left;">
@@ -197,40 +197,14 @@ const marketingWidgetScript = 'https://widget.socialproof.dev/v1/widget.js';
           <script src={marketingWidgetScript} async></script>
         </>
       ) : (
-        <div style="display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:24px;margin-top:48px;text-align:left;">
-          <div style="background:var(--bg-alt);border-radius:16px;padding:28px;border:1px solid var(--border);">
-            <div style="display:flex;gap:4px;margin-bottom:16px;font-size:18px;">⭐⭐⭐⭐⭐</div>
-            <p style="font-size:15px;line-height:1.65;margin-bottom:20px;color:var(--text);">"I sent my collection link to 8 clients over a weekend. By Monday I had 6 testimonials sitting in my dashboard. I'd been putting this off for two years."</p>
-            <div style="display:flex;align-items:center;gap:12px;">
-              <div style="width:40px;height:40px;background:linear-gradient(135deg,#6d28d9,#4f46e5);border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:15px;flex-shrink:0;">S</div>
-              <div>
-                <p style="font-weight:700;font-size:14px;margin:0;">Sarah K.</p>
-                <p style="color:var(--text-muted);font-size:13px;margin:0;">Life Coach, Portland OR</p>
-              </div>
-            </div>
-          </div>
-          <div style="background:var(--bg-alt);border-radius:16px;padding:28px;border:1px solid var(--border);">
-            <div style="display:flex;gap:4px;margin-bottom:16px;font-size:18px;">⭐⭐⭐⭐⭐</div>
-            <p style="font-size:15px;line-height:1.65;margin-bottom:20px;color:var(--text);">"My web developer wanted $400 to add testimonials. SocialProof cost me nothing and took 10 minutes. The embed just works. I genuinely can't believe this is free."</p>
-            <div style="display:flex;align-items:center;gap:12px;">
-              <div style="width:40px;height:40px;background:linear-gradient(135deg,#059669,#10b981);border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:15px;flex-shrink:0;">M</div>
-              <div>
-                <p style="font-weight:700;font-size:14px;margin:0;">Marcus T.</p>
-                <p style="color:var(--text-muted);font-size:13px;margin:0;">Wedding Photographer, Austin TX</p>
-              </div>
-            </div>
-          </div>
-          <div style="background:var(--bg-alt);border-radius:16px;padding:28px;border:1px solid var(--border);">
-            <div style="display:flex;gap:4px;margin-bottom:16px;font-size:18px;">⭐⭐⭐⭐⭐</div>
-            <p style="font-size:15px;line-height:1.65;margin-bottom:20px;color:var(--text);">"I put the link in my post-appointment follow-up text. I now get 2–3 new testimonials every week without thinking about it. It's running on autopilot."</p>
-            <div style="display:flex;align-items:center;gap:12px;">
-              <div style="width:40px;height:40px;background:linear-gradient(135deg,#dc2626,#f97316);border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:15px;flex-shrink:0;">J</div>
-              <div>
-                <p style="font-weight:700;font-size:14px;margin:0;">Jamie R.</p>
-                <p style="color:var(--text-muted);font-size:13px;margin:0;">Hair Salon Owner, Chicago IL</p>
-              </div>
-            </div>
-          </div>
+        <div style="max-width:640px;margin:48px auto 0;background:var(--bg-alt);border-radius:20px;padding:48px 40px;border:1px solid var(--border);text-align:center;">
+          <p style="font-size:40px;margin:0 0 16px;">🌱</p>
+          <h3 style="font-size:20px;font-weight:700;margin:0 0 12px;">Be one of our first featured customers</h3>
+          <p style="font-size:15px;line-height:1.65;color:var(--text-muted);margin:0 0 24px;">We're just getting started. Try SocialProof free — when you collect your first real testimonials, we'd love to feature your story right here.</p>
+          <a href="https://app.socialproof.dev/signup" class="btn btn-primary" style="display:inline-flex;align-items:center;gap:8px;">
+            Start free — get your first testimonial today →
+          </a>
+          <p style="font-size:13px;color:var(--text-muted);margin:16px 0 0;">No credit card. Free forever for 1 active widget.</p>
         </div>
       )}
     </div>