Refine onboarding: collapse "Why bother?" for a lighter first view; update Suan Luang Backyard tagline

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/pages/OnboardingPage.tsx

@@ -269,9 +269,9 @@ export default function OnboardingPage() {
 
         <div className="space-y-6">
 
-          {/* ── Why skaters care ── */}
+          {/* ── Why skaters care (collapsed by default — keeps the first view light) ── */}
           <section>
-            <h2 className="text-xs font-black uppercase tracking-widest text-gray-600 mb-4">Why bother?</h2>
+            <CollapsibleSection title="Why bother?">
             <div className="grid sm:grid-cols-2 gap-3">
               {[
                 {
@@ -304,6 +304,7 @@ export default function OnboardingPage() {
                 </div>
               ))}
             </div>
+            </CollapsibleSection>
           </section>
 
           {/* ── What you can do ── */}

src/pages/SupportersPage.tsx

@@ -73,7 +73,7 @@ const FRIENDS: Friend[] = [
     name: 'Suan Luang Backyard',
     logo: 'https://blossom.ditto.pub/8ac40ffbf9db9c9bff20e9b34d627a31b9c2044fe4f534948292516319684523.jpeg',
     url: 'https://www.slbskate.com/',
-    tagline: 'Backyard skate spot & community',
+    tagline: "Bangkok's most famous Backyard DIY Spot",
   },
   // Add more friends here
 ];