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/unified_search_bar.dart

@@ -40,7 +40,7 @@ class UnifiedSearchBar extends StatelessWidget {
                 decoration: BoxDecoration(
                   color: ShadcnTheme.card,
                   borderRadius: BorderRadius.circular(ShadcnTheme.radiusMd),
-                  border: Border.all(color: Colors.black),
+                  border: Border.all(color: ShadcnTheme.border),
                 ),
                 child: TextField(
                   controller: controller,
@@ -77,7 +77,7 @@ class UnifiedSearchBar extends StatelessWidget {
                   text: '검색',
                   onPressed: onSearch,
                   variant: ShadcnButtonVariant.primary,
-                  textColor: Colors.white,
+                  textColor: ShadcnTheme.primaryForeground,
                   icon: const Icon(Icons.search, size: 16),
                 ),
               ),
@@ -106,4 +106,4 @@ class UnifiedSearchBar extends StatelessWidget {
       ],
     );
   }
-}
+}