feat: add C# and Dart language support

rules/dart/hooks.md

@@ -0,0 +1,66 @@
+---
+paths:
+  - "**/*.dart"
+  - "**/pubspec.yaml"
+  - "**/analysis_options.yaml"
+---
+# Dart/Flutter Hooks
+
+> This file extends [common/hooks.md](../common/hooks.md) with Dart and Flutter-specific content.
+
+## PostToolUse Hooks
+
+Configure in `~/.claude/settings.json`:
+
+- **dart format**: Auto-format `.dart` files after edit
+- **dart analyze**: Run static analysis after editing Dart files and surface warnings
+- **flutter test**: Optionally run affected tests after significant changes
+
+## Recommended Hook Configuration
+
+```json
+{
+  "hooks": {
+    "PostToolUse": [
+      {
+        "matcher": { "tool_name": "Edit", "file_paths": ["**/*.dart"] },
+        "hooks": [
+          { "type": "command", "command": "dart format $CLAUDE_FILE_PATHS" }
+        ]
+      }
+    ]
+  }
+}
+```
+
+## Pre-commit Checks
+
+Run before committing Dart/Flutter changes:
+
+```bash
+dart format --set-exit-if-changed .
+dart analyze --fatal-infos
+flutter test
+```
+
+## Useful One-liners
+
+```bash
+# Format all Dart files
+dart format .
+
+# Analyze and report issues
+dart analyze
+
+# Run all tests with coverage
+flutter test --coverage
+
+# Regenerate code-gen files
+dart run build_runner build --delete-conflicting-outputs
+
+# Check for outdated packages
+flutter pub outdated
+
+# Upgrade packages within constraints
+flutter pub upgrade
+```