iEduPortal API v1 — Stage 14

Adds protected, read-only fee/billing retrieval:
- /api/v1/fees/

Returns:
- fee obligations from payable joined with fee/pupil/class details
- family payment history from fee_paid
- family deduction history from fee_deducted

Access rules:
- Pupil/student: own obligations and linked parent's payment/deduction history.
- Parent: obligations for their children and their own payment/deduction history; pupil_id is validated against the parent.
- Admin: permitted.
- Staff: permitted only for accountant, frontdesk, admin, headteacher, or super_admin roles.

Optional filters:
- pupil_id
- session
- term
- limit (1-100)
- offset

Read-only. No schema changes and no SQL import required.
