Initial commit: two Clojure Android todo apps

Side-by-side comparison of viable Clojure-on-Android approaches:
- todo-expo/: ClojureScript + shadow-cljs + Expo + Reagent + re-frame
- todo-flutter/: ClojureDart + Flutter

Both apps feature: add/remove/check-off todos, SQLite persistence,
categories, priorities, edit support, swipe-to-delete, filtering.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

todo-flutter/macos/RunnerTests/RunnerTests.swift

@@ -0,0 +1,12 @@
+import Cocoa
+import FlutterMacOS
+import XCTest
+
+class RunnerTests: XCTestCase {
+
+  func testExample() {
+    // If you add code to the Runner application, consider adding tests here.
+    // See https://developer.apple.com/documentation/xctest for more information about using XCTest.
+  }
+
+}