feat(content): deepen Bain differentiation across product, solution and service pages

- Replace decorative numbering and side-stripe borders with structured copy
- Add scenario positioning, capability metrics and verifiable dimensions
- Refine service timelines, deliverables and case-study narratives
- Update content constants to support CMS seeding

src/app/(marketing)/contact/contact-content-v3.tsx

@@ -220,7 +220,7 @@ function ContactFormContent({ data }: { data: ContactData }) {
               initial={{ opacity: 0, y: 20 }}
               animate={{ opacity: 1, y: 0 }}
               transition={{ duration: 0.8, delay: 0.1, ease: EASE_OUT }}
-              className="text-sm font-mono tracking-[0.2em] text-text-muted uppercase mb-8"
+              className="text-sm font-mono tracking-[0.15em] text-text-muted mb-8"
             >
               {data.heroSubtitle || ''}
             </motion.div>