feat(hyprland): generate Lua monitor config instead of hyprlang

Write hl.monitor({...}) calls to ~/.config/hypr/monitors.lua (loaded via
require("monitors") in hyprland.lua) instead of monitor= lines in
monitors.conf. Prepare now strips hl.monitor lines with disabled = true,
and generateConf omits mode/position so Hyprland uses its defaults.
Update README and example config to match.

internal/config/config.go

@@ -53,7 +53,7 @@ type Config struct {
 	// OutputPath overrides the generated monitor config file path.
 	// Supports ~ for home directory expansion.
 	// Deprecated: use backend_config.output_path instead.
-	// Empty means the default: ~/.config/hypr/monitors.conf.
+	// Empty means the default: ~/.config/hypr/monitors.lua.
 	OutputPath string `yaml:"output_path"`
 
 	// BackendConfig holds backend-specific configuration options.