feat: support smol:// QR sharing, deep links and in-dialog scanning

test/link_test.dart

@@ -0,0 +1,45 @@
+// Deep links: only smol:// URIs react, and only the native parser's verdict
+// decides that — the format rules stay in fumi, not a Dart copy of them.
+
+import "package:flutter_test/flutter_test.dart";
+
+import "package:smol_mail/smol/link.dart";
+
+const key = "lm2gqd7e5q67xq3isc5hx6jfj2q7a7xvq4l7trctxipudujovmgq";
+
+void main() {
+  test("self-certifying URI carries its key", () {
+    final link = parseSmolLink("smol://alice@example.org/$key");
+    expect(link, isNotNull);
+    expect(link!.address.identity, key);
+    expect(link.address.user, "alice");
+    expect(link.address.host, "example.org");
+    expect(link.address.port, 1961);
+    expect(link.source, "smol://alice@example.org/$key");
+  });
+
+  test("a non-default port is kept", () {
+    final link = parseSmolLink("smol://alice@example.org:1962/$key");
+    expect(link!.address.port, 1962);
+  });
+
+  test("a smol:// URI without its key is not a link", () {
+    // fumi rejects this form, so a truncated scan acts on nothing rather
+    // than importing a key the sender never signed into.
+    expect(parseSmolLink("smol://alice@example.org"), isNull);
+  });
+
+  test("other schemes are not ours", () {
+    expect(parseSmolLink("https://example.org/a"), isNull);
+    expect(parseSmolLink("mailto:alice@example.org"), isNull);
+  });
+
+  test("scheme-less addresses are not deep links", () {
+    expect(parseSmolLink("alice@example.org"), isNull);
+  });
+
+  test("a smol:// URI the parser rejects is ignored", () {
+    expect(parseSmolLink("smol://not a uri"), isNull);
+    expect(parseSmolLink("smol://alice@example.org/tooshort"), isNull);
+  });
+}