The zone grid was previously restricted to pool-type facilities only.
Now any facility can have a grid configured (rows × cols, max 25 each)
via the create/edit forms. Facilities with grid dimensions get the
visual grid manager; those without keep the unit-based mirror view.

Changes:
- Remove facility_type='pool' filter from PoolGridService::getFacility
- MirrorController routes by grid dimensions instead of facility type
- Facility create/edit forms now include grid rows/cols fields
- FacilityController store/update save grid dimensions
- Facility model fillable updated with grid columns
- Grid size limit increased from 20 to 25
- Facility show page adds "الشبكة" button when grid is configured
- MirrorStateService and SlotAvailabilityService check grid dims
  instead of facility_type for zone booking cross-checks
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>