fix: read back sent copies after the sec 5.6 upstream fix, pinned at 2d65d66

lib/smol/address.dart

@@ -0,0 +1,48 @@
+// Address forms (SPEC.md §3): parsing goes through the native library, so
+// the username rules are fumi's, not a reimplementation that can drift.
+
+import "package:smol_mail/native/ffi.dart";
+import "package:smol_mail/smol/errors.dart";
+
+/// One parsed address. [identity] carries the self-certifying key a
+/// smol:// URI binds; a short form has none until it is resolved.
+class SmolAddress {
+  final String user;
+  final String host;
+  final int port;
+  final String? identity;
+  final bool rns;
+
+  const SmolAddress(this.user, this.host, this.port,
+      {this.identity, this.rns = false});
+
+  /// The short form a contact list shows; the default port is elided.
+  String get short => rns
+      ? "smol+rns://$user@$host"
+      : "$user@$host${port == defaultPort ? "" : ":$port"}";
+
+  /// The self-certifying form: the key inside makes the address verifiable.
+  String uri(String publicKey) => rns
+      ? "smol+rns://$user@$host/$publicKey"
+      : "smol://$user@$host${port == defaultPort ? "" : ":$port"}/$publicKey";
+}
+
+const defaultPort = 1961;
+
+/// Parses any of the four address forms. Throws [SmolError] on anything
+/// else — the onboarding and compose fields validate through this.
+SmolAddress parseAddress(String text) {
+  final Map<String, dynamic> parsed;
+  try {
+    parsed = SmolFfi.open().parseAddress(text.trim());
+  } on NativeSmolException catch (err) {
+    throw SmolError(err.message);
+  }
+  return SmolAddress(
+    parsed["user"] as String,
+    parsed["host"] as String,
+    parsed["port"] as int,
+    identity: parsed["identity"] as String?,
+    rns: parsed["scheme"] == "rns",
+  );
+}