build(todo): emoji_picker_flutter, for reactions (ADR 0033, D36)

MIT, every platform Todo builds for, recents kept on the device.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/todo/halkyon_todo_flutter/pubspec.yaml

@@ -14,6 +14,9 @@ resolution: workspace
 
 dependencies:
   clock: ^1.1.3
+  # Reactions on comments (ADR 0033, D36): every emoji, searched, recents on
+  # the device.
+  emoji_picker_flutter: ^4.5.4
   equatable: ^3.0.0
   flutter:
     sdk: flutter