Gradebook: migrate legacy tool to Vue and Symfony

[christianbeeznest]

Summary

Migrates the course Gradebook from the legacy PHP interface to Vue 3 and Symfony/API Platform while preserving the existing Gradebook behavior.

Main changes

• Migrates Gradebook categories, evaluations and linked course activities.
• Adds modern Gradebook reports, statistics, history and learner views.
• Migrates certificate generation, certificate management and skills integration.
• Supports CSV, XML, XLSX, DOCX, PDF and print exports.
• Preserves Gradebook settings, calculations, locking and visibility rules.
• Supports weighted average and points sum calculation modes.
• Integrates Exercises, Assignments, Forums, Surveys, Attendance and Learning Paths with the modern Gradebook.
• Uses Doctrine and Symfony Providers/Processors instead of legacy Gradebook helpers for migrated integrations.
• Preserves course/session context and permission checks.
• Updates Course Home and related navigation to use the Vue Gradebook.
• Keeps a few explicit compatibility boundaries for legacy plugins and advanced certificate handling.

Validation

• Symfony cache clear: OK
• Vue build: OK
• PHP syntax checks: OK
• JavaScript syntax checks: OK
• git diff --check: OK
• Functional tests performed with teacher and learner roles.
• Tested Gradebook links with Exercises, Assignments, Forums, Surveys, Attendance and Learning Paths.
• Tested certificate generation and Gradebook skill assignment.