Display allocation warning during pending LSF approval (#622)

[DanielRukwasha]

Closes #622

Adds a non-blocking over-allocation warning to the pending-LSF approval confirmation modal, so Labor Office admins can see the allocation impact before approving.

• Extracted the allocation-counting logic from Create Current Allocation Card for the Department Portal #602's Department Portal card into a shared \�pp/logic/allocation.py\ (\getAllocationSummary, \getAllocationWarning), so this reuses the exact same 'used' counting (non-denied LaborStatusForms) instead of duplicating queries.
• \modal_approval_and_denial_data()\ now returns one allocation warning per unique department among the selected forms, alongside the existing per-form table data.
• The approval modal (\pendingApprovalModal.html\ / \�llPendingForms.js) renders a warning box per department: blue if within allocation, amber if any category is over. Positions and Break Hours are highlighted independently per the issue's requirement ('highlight any allocation categories that exceed'), since a department can be over on one and fine on the other.
• Fixed a pre-existing demo-data gap found while testing: no student/supervisor was ever marked \isActive, so the approval checkbox (which requires both to be active) never rendered at all in this environment.

Branched off \�llocation-card-real-data-ruk\ (not \�llocation_card\ directly) since this depends on the allocation logic from #636, which hasn't merged yet.

Tested via direct API calls and in-browser: confirmed the warning shows correct numbers, confirmed the red/amber highlighting triggers independently for positions-only and break-hours-only over-allocation scenarios, and confirmed the full approve flow completes correctly end-to-end.