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/ios/Runner.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:Runner.xcodeproj">
+   </FileRef>
+</Workspace>