Feature: Add Printable Weekly Student and Top-5 Achievement Certificates

[intelliraff]

Summary

This PR introduces printable weekly student certificates and Top-5 achievement certificates for Teacher and Volunteer users.

Changes Made

• Added weekly certificates to individual student profiles
• Added Top-5 achievement certificates to the performance dashboard
• Added class-specific normal certificate designs
• Included student details, current FLN level, learning streak, class rank, issue date, and teacher name
• Added the FLN Portal heading to Top-5 certificates
• Implemented accurate A4 landscape printing at 297mm × 210mm
• Restricted certificate access to Teacher and Volunteer users
• Preserved existing student-data loading and frontend functionality

Benefits

• Recognizes weekly student progress and achievement
• Allows teachers and volunteers to print professional certificates
• Highlights Top-5 student performance
• Produces consistent, print-ready A4 certificates
• Prevents unauthorized certificate access from School-level accounts
• Uses existing student roster data without requiring additional API calls

Testing

• Verified normal and Top-5 certificate rendering
• Verified A4 landscape print dimensions
• Verified normal certificates print without top offset
• Verified School users cannot access certificate features
• Verified Teacher and Volunteer access remains available
• Verified frontend TypeScript checks pass
• Verified the frontend production build succeeds