QR code scan/share for meta-addresses

[truthixify]

Tier: S (½-1 day) Type: feature

Context

good-first-issue

Scope

Mobile users want to share meta-addresses via QR. Demo already renders QRs for payment links (PR #34) but not for raw meta-addresses on the Receive page.

Acceptance criteria

• Add "Show QR" button next to displayed meta-address on Receive
• Modal with QR + copyable text + share button
• Camera-scan input on Send (use existing meta-address input)
• Use qrcode.react + react-qr-reader

Files to start with

• QR display modal
• Scan input on Send
• Mobile-tested
• A11y: button has aria-label, modal is keyboard-navigable

Why this matters

• src/components/StellarReceive.tsx, StellarSend.tsx