feat: QR pairing for wallet import (backend + website)

- Backend: nullable wallet_number on wallet_share_requests (migration 0029);
  createPairingRequest + POST /api/patients/wallet/pair; applyShareResponse
  binds the authenticated wallet on QR (pairing) requests
- Frontend: Import dialog gains a "Show QR" mode rendering a temetro-pair QR
  (react-qr-code) the patient scans; requestWalletPairing helper; i18n keys

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/lib/i18n/locales/en/translation.json

@@ -186,6 +186,11 @@
     "importApp": {
       "title": "Import from a patient app",
       "description": "Enter the patient's wallet number. They'll get a request on their phone to approve sharing their record with this clinic.",
+      "tabNumber": "By number",
+      "tabQr": "Show QR",
+      "qrHint": "Generate a QR code, then have the patient scan it in their wallet app to share their record.",
+      "qrCaption": "Scan this in the patient app",
+      "generateQr": "Show QR code",
       "walletLabel": "Patient wallet number",
       "walletPlaceholder": "tmw_…",
       "tempLabel": "Share temporarily",

frontend/lib/patients.ts

@@ -213,6 +213,21 @@ export async function requestWalletShare(input: {
   });
 }
 
+// Create a QR pairing request (no wallet number — the patient scans a QR that
+// carries this clinic's relay URL + the request). Returns the request plus the
+// ephemeral public key the device seals to.
+export type WalletPairing = WalletShareRequest & { ephemeralPubKey: string };
+
+export async function requestWalletPairing(input: {
+  mode: WalletShareMode;
+  durationHours?: number;
+}): Promise<WalletPairing> {
+  return apiFetch<WalletPairing>("/api/patients/wallet/pair", {
+    method: "POST",
+    body: JSON.stringify(input),
+  });
+}
+
 // Poll a request until the patient approves/denies on their device.
 export async function pollWalletShare(
   id: string,