adding category slider

lib/Screens/pos_sale/pos_sale.dart

@@ -536,6 +536,57 @@ class _PosSaleScreenState extends ConsumerState<PosSaleScreen> {
                   ],
                 ),
                 const SizedBox(height: 16),
+                categoryData.when(
+                  data: (data) {
+                    return SizedBox(
+                      height: 50,
+                      child: ListView.builder(
+                        itemCount: data.length + 1,
+                        scrollDirection: Axis.horizontal,
+                        itemBuilder: (context, index) {
+                          return GestureDetector(
+                            onTap: () {
+                              setState(() {
+                                selectedCategory = index == 0 ? null : data[index - 1];
+                                _applyFilters();
+                              });
+                            },
+                            child: Container(
+                              margin: EdgeInsets.only(left: index == 0 ? 0 : 8),
+                              decoration: BoxDecoration(
+                                borderRadius: BorderRadius.circular(5.0),
+                                color: (index == 0 && selectedCategory == null) ||
+                                        (index != 0 && selectedCategory?.id == data[index - 1].id)
+                                    ? kMainColor
+                                    : kMainColor.withOpacity(0.1),
+                              ),
+                              padding: const EdgeInsets.all(10),
+                              child: Center(
+                                child: Text(
+                                  index == 0 ? lang.S.of(context).all : data[index - 1].categoryName ?? '',
+                                  style: TextStyle(
+                                    fontSize: 14,
+                                    color: (index == 0 && selectedCategory == null) ||
+                                            (index != 0 && selectedCategory?.id == data[index - 1].id)
+                                        ? Colors.white
+                                        : kMainColor,
+                                  ),
+                                ),
+                              ),
+                            ),
+                          );
+                        },
+                      ),
+                    );
+                  },
+                  error: (Object error, StackTrace stackTrace) {
+                    return Text(error.toString());
+                  },
+                  loading: () {
+                    return const Center(child: CircularProgressIndicator());
+                  },
+                ),
+                const SizedBox(height: 16),
                 if (filteredProducts.isEmpty)
                   Text(lang.S.of(context).noMatched, style: _theme.textTheme.bodyMedium)
                 else