fix:新增获取分类的api，一个提供给管理员使用，一个提供给用户使用

src/main/java/com/campus/trade/controller/CategoryController.java

@@ -0,0 +1,28 @@
+package com.campus.trade.controller;
+
+import com.campus.trade.common.Result;
+import com.campus.trade.entity.Category;
+import com.campus.trade.service.admin.CategoryService;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/categories")
+@Tag(name = "Categories", description = "物品分类（公开接口）")
+public class CategoryController {
+
+    @Autowired
+    private CategoryService categoryService;
+
+    @Operation(summary = "获取所有分类列表", operationId = "listCategories")
+    @GetMapping
+    public Result<List<Category>> list() {
+        return Result.success(categoryService.list());
+    }
+}

src/main/java/com/campus/trade/controller/admin/CategoryController.java

@@ -22,6 +22,12 @@ public class CategoryController {
     @Autowired
     private CategoryService categoryService;
 
+    @Operation(summary = "获取所有分类列表", operationId = "adminListCategories")
+    @GetMapping
+    public Result<List<Category>> list() {
+        return Result.success(categoryService.list());
+    }
+
     @Operation(summary = "新增分类", operationId = "createCategory")
     @PostMapping
     public Result<Long> create(@Valid @RequestBody CategoryRequest req) {

src/main/java/com/campus/trade/service/admin/CategoryService.java

@@ -16,6 +16,11 @@ public class CategoryService {
     @Autowired
     private CategoryMapper categoryMapper;
 
+    // 分类列表
+    public List<Category> adminList() {
+        return categoryMapper.selectAll();
+    }
+
     // 分类列表（只返回启用的分类）
     public List<Category> list() {
         return categoryMapper.selectEnabled();