Add SummaryStep, PaymentStep, ConfirmationStep (wizard steps 13-15)

SummaryStep (step 13):
- Accordion sections with edit IconButtons linking back to each step
- dl/dt/dd definition list for label-value pairs
- Total bar with prominent price display (aria-live)
- Share plan icon button, deposit display
- Pre-planning: "Save your plan" CTA; at-need: "Confirm" CTA

PaymentStep (step 14):
- Payment plan (full/deposit) shown before method (amount before how)
- ToggleButtonGroup for plan + method selection
- Card: PayWay iframe slot with placeholder; Bank: account details display
- Terms checkbox with service agreement + privacy links
- Security reassurance (lock icon, no-surprise copy)

ConfirmationStep (step 15):
- Terminal page — no back button, no progress indicator
- At-need: "submitted" + callback timeframe + arranger contact
- Pre-planning: "saved" + return-anytime + family-ready copy
- Muted success icon (not celebratory), next-steps link buttons
- VenueCard selected prop also staged (from step 7 work)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/pages/SummaryStep/index.ts

@@ -0,0 +1,2 @@
+export { SummaryStep, default } from './SummaryStep';
+export type { SummaryStepProps, SummarySection, SummaryLineItem } from './SummaryStep';