Cleanup before release

[flopper123]

Pre-Release Cleanup

• Updated copyright year from 2024 to 2026
• Removed outdated "track_logged_in" feature claims from readme.txt (feature list, FAQ, and changelog)
• Fixed Dashboard link in plugin action links to use static URL (removed site_id suffix and conditional check)

Bug Fixes

• Fixed server_url being reset to default when saving settings (now only updates if explicitly provided in form input)
• Fixed wp_localize_script not checking the enabled subkey for trackDownloads and trackCustomHtmlAttr options
• Fixed empty event properties outputting as [] instead of {} by adding JSON_FORCE_OBJECT flag

Feature Rename: track_css_events to track_custom_html_attribute

• Renamed option key from track_css_events to track_custom_html_attribute across all files
• Updated JavaScript config property from trackCssEvents to trackCustomHtmlAttr
• Updated UI label from "CSS Class Events" to "Custom HTML Attribute Events"
• Updated description text to reference data-betterlytics-event attribute

Demo Environment Improvements

• Added pretty permalinks setup to demo-setup script in docker-compose.yml
• Added mu-plugins volume mount to main WordPress container so demo page renders correctly
• Added "Dashboards" link to demo test page Quick Links section
• Added "HTML Attribute Testing" section to demo test page
• Updated demo config to have tracking disabled by default with empty site_id