syncable-cli 0.22.3

# Color Adaptation Implementation Summary

## Overview

This implementation adds intelligent color adaptation to the syncable-cli tool, automatically adjusting terminal colors based on the user's terminal background (dark vs light) to ensure optimal readability across different terminal environments.

## Problem Solved

The original CLI used hardcoded colors optimized for dark terminals, making output difficult to read on light terminal backgrounds. This included both content colors and UI element labels (like "Type:", "Languages:", "Dockerfiles:", etc.) that were hardcoded to bright white, creating accessibility issues and poor user experience for users with light terminal themes.

## Solution Architecture

### Core Components

#### 1. ColorAdapter (`src/analyzer/display/color_adapter.rs`)
- **Main Logic**: Central color adaptation system
- **Detection**: Automatic terminal background detection using environment variables and heuristics
- **Color Schemes**: Dark and Light theme implementations
- **Global State**: Thread-safe singleton pattern using `OnceLock`

#### 2. ColorScheme Enum
```rust
pub enum ColorScheme {
    Dark,   // Dark background terminals
    Light,  // Light background terminals
}
```

#### 3. CLI Integration (`src/cli.rs`)
```rust
pub enum ColorScheme {
    Auto,   // Auto-detect (default)
    Dark,   // Force dark theme
    Light,  // Force light theme
}
```

### Detection Methods

1. **COLORFGBG Environment Variable**: Parses `foreground;background` format
2. **Terminal Program Detection**: Identifies specific terminal applications
3. **Heuristic Fallback**: Defaults to dark theme when detection fails

### Color Mapping Strategy

#### Dark Theme Colors
- Headers: `bright_white().bold()`
- Borders: `bright_blue()`
- Primary: `yellow()`
- Secondary: `green()`
- Languages: `blue()`
- Frameworks: `magenta()`
- Databases: `cyan()`

#### Light Theme Colors
- Headers: `black().bold()`
- Borders: `blue()`
- Primary: `red().bold()`
- Secondary: `green().bold()`
- Languages: `blue().bold()`
- Frameworks: `magenta().bold()`
- Databases: `cyan().bold()`

## Implementation Details

### 1. Color Adapter Methods
```rust
impl ColorAdapter {
    pub fn new() -> Self                    // Auto-detect
    pub fn with_scheme(scheme: ColorScheme) // Manual override
    pub fn header_text(&self, text: &str)  // Header styling
    pub fn primary(&self, text: &str)      // Primary content
    pub fn language(&self, text: &str)     // Language colors
    // ... 20+ color methods for different content types
}
```

### 2. Global State Management
```rust
static COLOR_ADAPTER: std::sync::OnceLock<ColorAdapter> = std::sync::OnceLock::new();

pub fn get_color_adapter() -> &'static ColorAdapter {
    COLOR_ADAPTER.get_or_init(ColorAdapter::new)
}

pub fn init_color_adapter(scheme: ColorScheme) {
    let _ = COLOR_ADAPTER.set(ColorAdapter::with_scheme(scheme));
}
```

### 3. CLI Integration
- Added `--color-scheme` option to analyze command
- Updated argument parsing in `main.rs` and `lib.rs`
- Modified handlers to accept and use color scheme parameter

### 4. Matrix View Updates
Replaced all hardcoded color calls:
```rust
// Before
println!("{}", "HEADER".bright_white().bold());
box_drawer.add_line("Type:", &arch_type.yellow(), true);

// After  
let colors = get_color_adapter();
println!("{}", colors.header_text("HEADER"));
box_drawer.add_line("Type:", &colors.project_type(&arch_type), true);
```

### 5. BoxDrawer Label Fix
Updated BoxDrawer to use color adapter for labels instead of hardcoded bright white:
```rust
// Before (in BoxDrawer)
let formatted_label = if line.label_colored && !line.label.is_empty() {
    line.label.bright_white().to_string()  // Always white - unreadable on light terminals
} else {
    line.label.clone()
};

// After (in BoxDrawer)
let formatted_label = if line.label_colored && !line.label.is_empty() {
    let colors = get_color_adapter();
    colors.label(&line.label).to_string()  // Adapts to terminal background
} else {
    line.label.clone()
};
```

## Files Modified

### Core Implementation
- `src/analyzer/display/color_adapter.rs` (NEW) - Main color adaptation logic
- `src/analyzer/display/mod.rs` - Module exports and re-exports
- `src/analyzer/display/matrix_view.rs` - Updated to use color adapter

### CLI Integration
- `src/cli.rs` - Added ColorScheme enum and CLI option
- `src/main.rs` - Updated command handling with color scheme parameter
- `src/lib.rs` - Updated run_command function
- `src/handlers/analyze.rs` - Updated to accept and initialize color scheme

### Testing and Documentation
- `examples/test_color_adaptation.rs` (NEW) - Comprehensive color testing
- `docs/COLOR_ADAPTATION.md` (NEW) - User documentation

## Usage Examples

### Automatic Detection (Default)
```bash
sync-ctl analyze my-project
```

### Manual Override
```bash
sync-ctl analyze my-project --color-scheme light
sync-ctl analyze my-project --color-scheme dark
sync-ctl analyze my-project --color-scheme auto
```

### Programmatic Usage
```rust
use syncable_cli::analyzer::display::{ColorAdapter, ColorScheme};

// Auto-detect
let adapter = ColorAdapter::new();

// Manual
let adapter = ColorAdapter::with_scheme(ColorScheme::Light);

// Apply colors
println!("{}", adapter.header_text("My Header"));
```

## Testing Strategy

### 1. Unit Tests
- Color adapter creation and scheme detection
- Color method functionality
- Global state management

### 2. Integration Testing
- CLI option parsing and propagation
- Color scheme initialization
- End-to-end color application

### 3. Visual Testing
- `test_color_adaptation.rs` example for manual verification
- Side-by-side comparison of dark/light themes
- Auto-detection verification

## Backward Compatibility

- **Default behavior**: Auto-detection maintains existing visual experience for most users
- **API stability**: All existing CLI commands continue to work unchanged
- **Graceful fallback**: Falls back to dark theme when detection fails

## Performance Considerations

- **Lazy initialization**: Color adapter created only when needed
- **Singleton pattern**: Single adapter instance per process
- **Minimal overhead**: Detection runs once at startup
- **No runtime costs**: Color methods are simple string formatting

## Future Enhancements

### Short Term
- More terminal program detection
- Better COLORFGBG parsing
- Configuration file support

### Long Term
- High contrast themes
- Colorblind-friendly schemes
- Per-command color preferences
- Dynamic theme switching

## Error Handling

- **Detection failures**: Graceful fallback to dark theme
- **Invalid schemes**: CLI validation prevents invalid values
- **Environment issues**: Robust parsing with safe defaults

## Dependencies Added

- None (uses existing `colored` crate)
- Minimal impact on compilation time
- No new external dependencies

## Compilation Impact

- Clean compilation after changes
- Only warnings related to existing unused code
- No breaking changes to existing functionality

## Deployment Considerations

- **Environment variables**: Users may need to set `COLORFGBG` for better detection
- **SSH/Remote**: May require manual override in some cases
- **CI/CD**: Auto-detection works in most automated environments