Fix issues with cache location setting

[MarcGuay]

Fixing issues with cache location described here #253

[Copilot]

Pull Request Overview

This PR fixes how the cache directory path is resolved and updates the admin UI text to document the cache directory behavior.

• Changed cache_dir_setting to prepend the base folder when a custom cache path is provided
• Removed redundant base-folder prefix in settings output for cache_dir
• Updated the admin description to include cache directory rules and defaults

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
wp-scss.php	Modified how $cache_dir_setting is determined and used in settings
options.php	Expanded the admin “Paths” section text to cover cache directory

Comments suppressed due to low confidence (1)

wp-scss.php:167

• Add unit tests for the cache directory logic to cover cases where cache_dir is empty, starts with /, and omits the leading slash to prevent regressions.

$cache_dir_setting = !empty($wpscss_options['cache_dir']) ? $base_compiling_folder.$wpscss_options['cache_dir'] : WPSCSS_PLUGIN_DIR . '/cache/';

[Copilot]

If the user-provided cache_dir value lacks a leading slash, concatenating it directly to $base_compiling_folder can produce an invalid path (/basepathcache/ instead of /basepath/cache/). Consider normalizing the input (e.g., ensure it starts with /) or using ltrim() and trailingslashit() to build the path.

[Copilot]

[nitpick] Use WordPress helper functions (e.g., trailingslashit() and ltrim()) when constructing filesystem paths to ensure consistent slash handling and readability.

Suggested change

	$cache_dir_setting = !empty($wpscss_options['cache_dir']) ? $base_compiling_folder.$wpscss_options['cache_dir'] : WPSCSS_PLUGIN_DIR . '/cache/';
	$cache_dir_setting = !empty($wpscss_options['cache_dir']) ? trailingslashit($base_compiling_folder) . ltrim($wpscss_options['cache_dir'], '/') : trailingslashit(WPSCSS_PLUGIN_DIR) . 'cache/';