feat(clipboard): add copy URL to clipboard functionality

[lucs7]

This pull request introduces a new feature that allows users to easily copy calendar subscription URLs (iCalendar and Atom feeds) to their clipboard with a single click, and provides immediate feedback via a toast notification.

[Copilot]

Pull request overview

This PR adds a “copy calendar subscription URL” interaction across schedule, calendar, and admin views by wiring subscription links to a clipboard helper and showing feedback via Bootstrap toasts.

Changes:

• Added global copyUrlToClipboard() and showToastById() helpers in phpscheduleit.js.
• Updated multiple Smarty templates so clicking Atom/iCalendar/Subscription links copies the URL (instead of navigating) and triggers a toast.
• Centralized toast markup in tpl/globalfooter.tpl and added a new UrlCopiedToClipboard translation string in several locales.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
Web/scripts/schedule.js	Uses the new global toast helper when setting a default schedule.
Web/scripts/phpscheduleit.js	Adds global toast + clipboard helper functions (with fallback).
tpl/Schedule/schedule.tpl	Converts schedule subscription links to copy-to-clipboard behavior.
tpl/globalfooter.tpl	Adds shared toast container/markup for clipboard + default-schedule feedback.
tpl/Calendar/mycalendar.subscription.tpl	Converts “Subscribe to calendar” link to copy-to-clipboard behavior and removes inline URL display.
tpl/Calendar/calendar.subscription.tpl	Converts calendar subscription link to copy-to-clipboard behavior.
tpl/Admin/Schedules/manage_schedules.tpl	Converts admin schedule Atom/iCalendar links to copy-to-clipboard behavior.
tpl/Admin/Resources/manage_resources_public.tpl	Converts admin resource Atom/iCalendar links to copy-to-clipboard behavior.
lang/pt_br.php	Adds UrlCopiedToClipboard translation (pt_BR).
lang/it_it.php	Adds UrlCopiedToClipboard translation (it_IT).
lang/fr_fr.php	Adds UrlCopiedToClipboard translation (fr_FR).
lang/es.php	Adds UrlCopiedToClipboard translation (es).
lang/en_us.php	Adds UrlCopiedToClipboard translation (en_US).
lang/de_de.php	Adds UrlCopiedToClipboard translation (de_DE).