✨feature: Wire up contact and thank you pages, add showInNav meta functionality

templates/thanks_page.html

@@ -0,0 +1,10 @@
+{{ define "thanks_page" }}
+{{ template "base" . }}
+{{ end }}
+
+{{ define "thanks_content" }}
+<div class="max-w-2xl mx-auto mt-10 text-center">
+  <h1 class="text-3xl font-bold text-green-700 mb-4">Thanks for reaching out!</h1>
+  <p class="text-lg">Your message has been received. I’ll get back to you as soon as I can.</p>
+</div>
+{{ end }}