fix: don't use mbstring
feat: sort graphs on the statistics page by usage
feat: lifetime subscriptions
feat: allow multiple filters on the settings page
feat: filter by notification status
fix: migrations using double quotes
feat: rework icons
fix: open 3 dot menu abone for the subscriptions at the bottom
fix: ntfy notifications with strange chars
feat: user has api key available on profile page
feat: api endpoint to calculate monthly cost
feat: split settings page into settings and profile page
feat: redesigned experimental mobile navigation menu
fix: small fixes and typos
refactor: run linter and cleanup php files
fix: not every payment cycle was shown on the calendar
feat: also show previous payments on the calendar for the current month
