Render textured aerial maps and support legacy recovery links

shared/legacy-recovery.ts

@@ -0,0 +1,6 @@
+// A previously issued recovery email can land at /code=<token> when its email
+// template omitted the callback route. Bring that link through verification.
+export function legacyRecoveryToken(pathname: string) {
+  const match = /^\/code=([A-Za-z0-9._~-]{8,2048})$/.exec(pathname);
+  return match?.[1] ?? null;
+}