Initial commit: TDD Workshop exercises for participants

- Password Validator kata with starter code and tests
- Shopping Cart kata with starter code and tests
- FizzBuzz reference code (from live demo)
- Setup guide and TDD reference card
- No solutions included (participants implement themselves)

.gitignore

@@ -0,0 +1,22 @@
+# Dart build artifacts
+.dart_tool/
+.packages
+pubspec.lock
+build/
+
+# IDE
+.idea/
+.vscode/
+*.iml
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Temporary files
+*.log
+*.tmp
+
+# FizzBuzz nested git repository (keep the .git for demo purposes)
+# The fizzbuzz/.git directory contains TDD progression commits
+# It's intentionally kept separate from the main workshop repo