feat: add pagination to learner profile loans

[EmeditWeb]

Problem

The LearnerProfile page fetches ALL loans for a learner at once with no pagination. As users accumulate loans, this will cause slow page loads.

Root Cause

The learner loans query lacks pagination parameters.

What To Build

1. Add pagination to the loans useQuery call in LearnerProfile.tsx
2. Add pagination controls below the loans list
3. Add loading state during page transitions

Files To Touch

• src/pages/LearnerProfile.tsx — add pagination

Acceptance Criteria

• Pagination controls on learner loans list
• Loading state during page changes
• Default 20 items per page

Mandatory Checks

• context/ files read
• npm run build passes
• PR references this issue