CodeIgniter Branch-Scoped Sessions Fix

My CodeIgniter application runs several branches under one database. The session layer is not respecting branch boundaries: an admin can end up seeing or affecting data outside their own branch or, worse, the session drops altogether.

Here’s what I need corrected:
• When an admin logs in, their session must be tied to a specific branch_id and stay that way until logout.
• That admin should have Edit permissions only within that branch and nothing beyond it.
• Within their branch they must be able to edit user accounts, branch details and inventory data.
• Sessions must persist normally (no unexpected time-outs) and never leak across branches.

The project uses CodeIgniter 3 with the standard session library (database driver). I’ll give you access to the Git repo and a staging DB dump so you can reproduce the problem. Deliver clean, well-commented PHP fixes plus any needed database tweaks or middleware changes; once merged I should be able to run a quick test, switch branches, and confirm isolation.

If you’ve hardened CI sessions before or built branch-level ACLs, this should be straightforward. Let me know how soon you can dive in and roughly how many hours you expect.