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/PromotionsPage.tsx

@@ -0,0 +1,37 @@
+import { Link } from 'react-router-dom'
+import { PageMeta } from '@/components/common/PageMeta'
+
+export default function PromotionsPage() {
+  return (
+    <>
+      <PageMeta title="Promotions" description="Active ResolutionFlow promotional offers and their terms." />
+      <div className="min-h-screen bg-background text-foreground">
+        <div className="mx-auto max-w-3xl px-6 py-16">
+          <Link to="/landing" className="text-sm text-muted-foreground hover:text-foreground mb-8 inline-block">&larr; Back to home</Link>
+          <h1 className="text-3xl font-bold font-heading mb-4">Promotions</h1>
+          <p className="text-muted-foreground mb-10">Last updated: May 7, 2026</p>
+
+          <div className="space-y-6 text-muted-foreground leading-relaxed">
+            <section>
+              <h2 className="text-xl font-semibold text-foreground mb-3">Current promotions</h2>
+              <p>No promotions are currently active.</p>
+              <p className="mt-3">
+                Promotional offers, when running, will be listed on this page with their specific terms (eligible plans, duration, redemption rules, expiration). The general terms that apply to all promotions are described in{' '}
+                <Link to="/policies" className="text-primary hover:underline">Section 6 of our Customer Policies</Link>.
+              </p>
+            </section>
+
+            <section>
+              <h2 className="text-xl font-semibold text-foreground mb-3">Questions</h2>
+              <p>
+                Email{' '}
+                <a href="mailto:billing@resolutionflow.com" className="text-primary hover:underline">billing@resolutionflow.com</a>{' '}
+                for questions about a promotion you received by email, or to ask about upcoming offers.
+              </p>
+            </section>
+          </div>
+        </div>
+      </div>
+    </>
+  )
+}