feat(ui): full‑width ShadTable across app; fix rent dialog width; correct equipment pagination

- ShadTable: ensure full-width via LayoutBuilder+ConstrainedBox minWidth
- BaseListScreen: default data area padding = 0 for table edge-to-edge
- Vendor/Model/User/Company/Inventory/Zipcode: set columnSpanExtent per column
  and add final filler column to absorb remaining width; pin date/status/actions
  widths; ensure date text is single-line
- Equipment: unify card/border style; define fixed column widths + filler;
  increase checkbox column to 56px to avoid overflow
- Rent list: migrate to ShadTable.list with fixed widths + filler column
- Rent form dialog: prevent infinite width by bounding ShadProgress with
  SizedBox and remove Expanded from option rows; add safe selectedOptionBuilder
- Admin list: fix const with non-const argument in table column extents
- Services/Controller: remove hardcoded perPage=10; use BaseListController
  perPage; trust server meta (total/totalPages) in equipment pagination
- widgets/shad_table: ConstrainedBox(minWidth=viewport) so table stretches

Run: flutter analyze → 0 errors (warnings remain).

lib/screens/common/widgets/standard_data_table.dart

@@ -306,7 +306,7 @@ class StandardDataRow extends StatelessWidget {
             ? ShadcnTheme.muted.withValues(alpha: 0.1)
             : null,
         border: Border(
-          bottom: BorderSide(color: Colors.black),
+          bottom: BorderSide(color: ShadcnTheme.border),
         ),
       ),
       child: Row(
@@ -418,4 +418,4 @@ class StandardActionButtons extends StatelessWidget {
       tooltip: tooltip,
     );
   }
-}
+}