feat(legal): add /policies, /contact, /promotions pages + MarketingFooter (#165)

Adds the three legal/contact pages needed for Stripe live-mode site review: /policies (consolidated customer policies — refunds, cancellation, legal restrictions, promotions), /contact (phone (470) 949-4131 + support/sales/billing/security inboxes), /promotions (stub satisfying §6.2 cross-ref).

Extracts the existing landing footer into components/common/MarketingFooter.tsx and mounts it on /pricing and /contact-sales so all four legal links are reachable from every marketing surface.

Privacy and Terms closing sections updated to point at /contact + /policies; stale hello@ mailto removed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Co-authored-by: Michael Chihlas <michael@resolutionflow.com>
Co-committed-by: Michael Chihlas <michael@resolutionflow.com>

frontend/src/pages/PricingPage.tsx

@@ -3,6 +3,7 @@ import { Link } from 'react-router-dom'
 
 import { plansApi, type PublicPlanResponse } from '@/api/plans'
 import { PageMeta } from '@/components/common/PageMeta'
+import { MarketingFooter } from '@/components/common/MarketingFooter'
 import { useAppConfig } from '@/hooks/useAppConfig'
 import '@/styles/landing.css'
 
@@ -431,6 +432,8 @@ export function PricingPage() {
         >
           Built on Stripe + AWS · Encrypted in transit and at rest
         </section>
+
+        <MarketingFooter />
       </main>
     </div>
   )