CI3 HR System Upgrade to CI4

I’m migrating my in-house HR platform from CodeIgniter 3 to CodeIgniter 4 and want to take the opportunity to modernise two core modules—Employee Management and Leave Management—without disturbing existing data or day-to-day operations.

What stays the same
• All current records and basic workflows must be carried over intact, with seamless database migration scripts so staff notice zero downtime.

What changes
Employee Management
• A refreshed, mobile-friendly interface (Bootstrap 5 or similar)
• New, drill-down reporting screens and exportable CSV/PDF summaries
• Hardened security: stronger hashing, CSRF protection, stricter role-based access, and audit logs

Leave Management
• Matching UI upgrade for a consistent look
• Automated approval chain that notifies the next approver and updates status in real time
• Clear tracking dashboard plus consolidated monthly/annual reports

Acceptance criteria
1. Full CI4 codebase that installs via Composer, follows namespacing conventions, and passes unit tests.
2. Migration scripts that convert CI3 tables, keys, and data with one command.
3. Updated views/controllers/models for both modules meeting the improvements above.
4. Documentation covering server requirements, install steps, and a short user guide for HR staff.
5. Final hand-over on a Git repo with commit history and README.

If you’ve completed similar CI3→CI4 upgrades—or larger Laravel refactors—please reference them in your proposal along with estimated milestone breakdowns for migration, feature build-out, testing, and deployment.