fix: Attempt to keep the weathermap basepath the weathermap directory

[TheWitness]

For some reason, after some timeout issues weathermap changed behavior to where the base-path was no longer set properly causing errors finding and loading Maps.

[Copilot]

Pull request overview

Removes chdir('../../') calls from plugin entry scripts and changes include paths to be relative, keeping the working directory at the weathermap plugin location so subsequent $config['base_path']-based includes resolve properly.

Changes:

• Drop chdir('../../') in four plugin entry scripts and use ../../include/... relative paths instead.
• Add CHANGELOG entry documenting the fix.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
weathermap-cacti-rebuild.php	Replace chdir + relative include with ../../include/cli_check.php.
weathermap-cacti-plugin.php	Replace chdir + relative include with ../../include/auth.php.
weathermap-cacti-plugin-mgmt.php	Replace chdir + relative include with ../../include/auth.php.
weathermap-cacti-plugin-editor.php	Replace chdir + relative include with ../../include/auth.php.
CHANGELOG.md	Document the basepath fix.