Restructures /join.vue per docs/specs/join-form-redesign.md:
- Split hero (1fr 1fr) matching about.vue rhythm: H1 + tagline on left,
"What you get" benefits on right (including "Pick your circle anytime
after signup")
- Form section (1fr 1fr): form on left, "About the money" trust copy on
right
- Inline PWYC editorial list with visually-hidden radio inputs for
keyboard accessibility; cadence-aware preset amounts ($0/$5/$15/$30/$50
monthly, ×12 annual); $15 row tagged "Suggested"
- Custom-amount row commits on blur and snaps to matching preset
- Cadence toggle (Monthly · Annual) in the section header; switching
multiplies/floor-divides both form.contributionAmount and the custom
amount display
- Removed: circle radio picker (defers to post-signup), ParchmentInset
"How membership works", bottom three-circle row
- Submit row: bare agreement checkbox + auto-width button, wraps at 480px
- form.circle stays initialized to "community" and submits unchanged
Tests updated for new markup (radio ids #pwyc-N, .submit-btn class).
Cadence/billing-summary and contribution-guidance tests retired with
the ContributionAmountField usage on this page.