Development: Replace bootstrap components with primeng in calendar

[marlonnienaber]

Checklist

General

• I tested all changes and their related features with all corresponding user types on a test server.
• Language: I followed the guidelines for inclusive, diversity-sensitive, and appreciative language.
• I chose a title conforming to the naming conventions for pull requests.

Client

• I strictly followed the client coding and design guidelines.
• Following the theming guidelines, I specified colors only in the theming variable files and checked that the changes look consistent in both the light and the dark theme.
• I added multiple integration tests (Jest) related to the features (with a high test coverage), while following the test guidelines.
• I added multiple screenshots/screencasts of my UI changes.

Motivation and Context

I initially implemented the calendar feature using a few bootstrap components. To improve UI/UX we want to use PrimeNG components in the future.

Description

This PR replaces all Bootstrap components used in the calendar feature with PrimeNG components. I mainly replaced controls (such as buttons) and popovers. I also adapted the tests to work with the new setup.

Steps for Testing

1. Choose either mobile phone or laptop as testing device and check the option below. Please choose an option that was not yet tested.
2. Visit this calendar.
3. Verify that all functionality still works (test in particular all controls. Test whether events are clickable in both presentations for the laptop and in the day presentation for mobile phone)

Testserver States

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Review Progress

Code Review

• Code Review 1
• Code Review 2

Manual Tests

• Test 1 (mobile phone)
• Test 2 (laptop)

Test Coverage

Client

Class/File	Line Coverage	Confirmation (assert/expect)
calendar-desktop-month-presentation.component.ts	100%	✅
calendar-desktop-overview.component.ts	96.84%	✅
calendar-desktop-week-presentation.component.ts	100%	✅
calendar-mobile-day-presentation.component.ts	100%	✅
calendar-mobile-overview.component.ts	92.95%	✅
calendar-event-detail-popover.component.ts	100%	✅
calendar-events-per-day-section.component.ts	95.71%	✅
calendar-util.ts	100%	✅

Screenshots

Summary by CodeRabbit

• New Features

  • New event detail popover with explicit open/close behavior and richer event details.
  • Desktop: multi-select event filters and compact presentation selector.
  • Mobile: popover-based filter panel, toggleable filter options, and streamlined header controls.

• Refactor

  • Simplified calendar interaction model and reactive state handling for presentations and filters.

• Style

  • Updated theme primary palette and refreshed chip/header/popover styling.

• Chores

  • Slightly relaxed client module coverage thresholds.

[github-actions]

End-to-End (E2E) Test Results Summary

	Tests	Passed ✅	Skipped	Failed	Time ⏱
End-to-End (E2E) Test Report	1 ran	1 passed	0 skipped	0 failed	1s 505ms

Test	Result	Time ⏱
No test annotations available

[Yhmidi]

test on laptop re-approved

[github-actions]

End-to-End (E2E) Test Results Summary

	Tests	Passed ☑️	Skipped ⚠️	Failed ❌️	Time ⏱
End-to-End (E2E) Test Report	205 ran	200 passed	3 skipped	2 failed	1h 14m 47s 673ms

Test	Result	Time ⏱
End-to-End (E2E) Test Report
e2e/exercise/quiz-exercise/QuizExerciseManagement.spec.ts
ts.Quiz Exercise Management › Quiz Exercise Creation › Creates a Quiz with Drag and Drop	❌ failure	2m 4s 549ms
e2e/exercise/programming/ProgrammingExerciseStaticCodeAnalysis.spec.ts
ts.Static code analysis tests › Configures SCA grading and makes a successful submission with SCA errors	❌ failure	2m 38s 270ms

[tobias-lippert]

code lgtm

[SamuelRoettgermann]

Re-Tested on mobile. Still works.

[ekayandan]

Approving code. Thanks for the changes!

[ekayandan]

Reapprove after fixing merge conflicts