Update documentation reflecting completed 6-arrow layout implementation

- Mark 6-arrow layout as completed in CLAUDE.md with architectural details
- Update current functionality descriptions for both 3-arrow and 6-arrow modes
- Reduce remaining UI priorities from 6 to 4 items
- Add gitignore patterns for layout documentation and user notes
- Update README.md with enhanced feature descriptions

Documentation now accurately reflects the stable static grid architecture
with logical grouping system and responsive percentage-based layout.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.gitignore

@@ -5,11 +5,9 @@
 *.swp
 .DS_Store
 .atom/
-.build/
 .buildlog/
 .history
 .svn/
-.swiftpm/
 migrate_working_dir/
 
 # IntelliJ related
@@ -25,13 +23,15 @@ migrate_working_dir/
 
 # Flutter/Dart/Pub related
 **/doc/api/
-**/ios/Flutter/.last_build_id
+**/ios/Flutter/Generated.xcconfig
+**/ios/Flutter/flutter_export_environment.sh
+**/ios/Flutter/app.dill
 .dart_tool/
+.flutter-plugins
 .flutter-plugins-dependencies
 .pub-cache/
 .pub/
 /build/
-/coverage/
 
 # Symbolication related
 app.*.symbols
@@ -44,8 +44,7 @@ app.*.map.json
 /android/app/profile
 /android/app/release
 
-# Designing references
-.uidesign/
-
-# human note
-NOTES.txt
+# Layout documentation - completed/incomplete status files
+*ARROW_LAYOUT.md
+COMPLETED_*.md
+INCOMPLETE_*.md