feat: Add YAML-based configuration system

- Add default_config.yaml with customizable settings
- Model selection (minicpm-v, llama3.2-vision, llava)
- Customizable vision prompt for better responses
- Timing parameters (idle threshold, response delay)
- Approval keywords configuration
- User config at ~/.config/claude-vision-auto/config.yaml
- New command: claude-vision-config to generate user config
- Environment variables still override config files
- Added PyYAML dependency

Configuration priority:
1. Environment variables (highest)
2. User config (~/.config/claude-vision-auto/config.yaml)
3. Default config (package default)

Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Jean-Philippe Brule <jp@svrnty.io>

bin/claude-vision-config

@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+"""
+Generate user configuration file for Claude Vision Auto
+"""
+
+import sys
+from pathlib import Path
+from claude_vision_auto.config import create_user_config, get_config_dir
+
+
+def main():
+    """Create user configuration file"""
+    config_path = create_user_config()
+
+    if config_path:
+        print(f"✅ Created user configuration file:")
+        print(f"   {config_path}")
+        print()
+        print("Edit this file to customize:")
+        print(f"   - Vision model (minicpm-v, llama3.2-vision, llava)")
+        print(f"   - Vision prompt for better responses")
+        print(f"   - Timing settings (idle threshold, response delay)")
+        print(f"   - Approval keywords")
+        print()
+        print(f"Edit with: nano {config_path}")
+    else:
+        config_dir = get_config_dir()
+        config_path = config_dir / "config.yaml"
+        print(f"ℹ️  Configuration file already exists:")
+        print(f"   {config_path}")
+        print()
+        print(f"Edit with: nano {config_path}")
+
+    sys.exit(0)
+
+
+if __name__ == '__main__':
+    main()