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>

.gitignore

@@ -0,0 +1,31 @@
+# Node
+node_modules/
+
+# Shadow-cljs
+.shadow-cljs/
+.nrepl-port
+
+# Expo / React Native
+todo-expo/app/
+todo-expo/.expo/
+todo-expo/android/
+todo-expo/ios/
+
+# Flutter / ClojureDart
+todo-flutter/build/
+todo-flutter/.clojuredart/
+todo-flutter/.dart_tool/
+todo-flutter/.cpcache/
+todo-flutter/.packages
+
+# Clojure
+.cpcache/
+
+# IDE
+.idea/
+*.iml
+.vscode/
+
+# OS
+.DS_Store
+Thumbs.db