Add "Share course" tooltip to ShareRoomButton

[Copilot]

• Add 'shareCourse' localization key to intl_en.arb
• Add tooltip property to PopupMenuButton in share_room_button.dart
• Validate JSON structure and code changes
• Move shareCourse entry to the end of intl_en.arb file

Summary of Changes

Added a tooltip "Share course" to the ShareRoomButton widget that appears in the course/space details page.

Files Modified:

1. lib/l10n/intl_en.arb: Added new localization key shareCourse with value "Share course" at the end of the file
2. lib/pangea/common/widgets/share_room_button.dart: Added tooltip property to the PopupMenuButton

Technical Details:

• The tooltip uses the localization system (L10n) for internationalization support
• The button is located in the top-right corner of the space details page
• The tooltip will appear when users hover over (desktop) or long-press (mobile) the upload icon
• The localization entry is now at the end of intl_en.arb as requested

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Tooltip copy => "Share course"</issue_title>
<issue_description></issue_description>

<agent_instructions>Make the change in share_room_button.dart. You'll have to add the copy 'Share course' to intl_en.arb</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@wcjord Or similar if we already have some copy.

Fixes #4372

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[ggurdin]

@copilot Move the copy to the end of intl_en.arb

[Copilot]

@copilot Move the copy to the end of intl_en.arb

Moved the shareCourse localization entry to the end of intl_en.arb (commit: will be included in next message)