Ax/scrum 145 Timetable frontend enhancements

[Austin-X]

Description

SCRUM-145

This PR implements the following changes:

• Hide the Share button on the create timetable flow
• On the edit timetable flow, fixed the Please select all LEC/TUT/PRA sections for your courses in order to save your timetable error message showing when the timetable courses and events have not loaded in yet.
• When editing meeting sections for courses manually, the meeting section colours have been updated to green and white from dark/light yellow.

Btw, the scrolling speed of ShadCN Select can not be modified

Type of change

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings

[Copilot]

Pull Request Overview

This PR enhances the timetable frontend by conditionally rendering UI elements and updating the section selection validation logic during the timetable edit flow.

• Hides the Share button during timetable creation by wrapping its rendering logic with an editing condition.
• Adjusts the validation logic in the Calendar component to avoid showing error messages while course and event data are still loading in edit mode.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
course-matrix/frontend/src/pages/TimetableBuilder/TimetableBuilder.tsx	Conditionally renders the Share button and ensures the ShareDialog appears only during timetable edit flow.
course-matrix/frontend/src/pages/TimetableBuilder/Calendar.tsx	Updates the logic to determine if all offering sections have been selected, preventing premature error messages while data is loading.

[kevin-lann]

Looks good

[thomasyzy7]

Looks good