feat(backend): 新增按街道ID统计家庭/成长规划师数量接口

支撑区域匹配页面：/api/admin/families/count 按 streetIds 统计家庭数，/api/admin/teachers/count 经家庭 teacher_id 去重统计规划师数。

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

cfc-backend/src/main/java/com/etotem/cfc/controller/admin/AdminController.java

@@ -19,6 +19,8 @@ import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.ArrayList;
+import java.util.Collections;
 
 @RestController
 @RequestMapping("/api/admin")
@@ -521,6 +523,69 @@ public class AdminController {
         return Result.success(true);
     }
 
+    /**
+     * 按街道ID列表统计家庭数量（区域匹配用）
+     */
+    @Operation(summary = "按街道ID列表统计家庭数量")
+    @PostMapping("/families/count")
+    public Result<Long> countFamiliesByStreetIds(@RequestBody Map<String, Object> params) {
+        List<Long> streetIds = parseStreetIds(params);
+        if (streetIds.isEmpty()) {
+            return Result.success(0L);
+        }
+        Long count = familyMapper.selectCount(new LambdaQueryWrapper<Family>()
+                .in(Family::getStreetId, streetIds));
+        return Result.success(count);
+    }
+
+    /**
+     * 按街道ID列表统计成长规划师数量（通过家庭 streetId 归属，teacher_id 去重）
+     */
+    @Operation(summary = "按街道ID列表统计成长规划师数量")
+    @PostMapping("/teachers/count")
+    public Result<Long> countTeachersByStreetIds(@RequestBody Map<String, Object> params) {
+        List<Long> streetIds = parseStreetIds(params);
+        if (streetIds.isEmpty()) {
+            return Result.success(0L);
+        }
+        // 统计这些街道下已绑定成长规划师的家庭，按 teacher_id 去重
+        List<Family> families = familyMapper.selectList(new LambdaQueryWrapper<Family>()
+                .in(Family::getStreetId, streetIds)
+                .isNotNull(Family::getTeacherId));
+        long count = families.stream()
+                .map(Family::getTeacherId)
+                .filter(java.util.Objects::nonNull)
+                .distinct()
+                .count();
+        return Result.success(count);
+    }
+
+    /**
+     * 解析请求中的 streetIds 参数（支持逗号分隔字符串或数组）
+     */
+    private List<Long> parseStreetIds(Map<String, Object> params) {
+        Object raw = params.get("streetIds");
+        if (raw == null) {
+            return Collections.emptyList();
+        }
+        String str = raw.toString();
+        if (str.isEmpty()) {
+            return Collections.emptyList();
+        }
+        List<Long> ids = new ArrayList<>();
+        for (String part : str.split(",")) {
+            String trimmed = part.trim();
+            if (!trimmed.isEmpty()) {
+                try {
+                    ids.add(Long.parseLong(trimmed));
+                } catch (NumberFormatException ignored) {
+                    // 忽略非数字片段
+                }
+            }
+        }
+        return ids;
+    }
+
     // 任务模板管理
     @PostMapping("/task-templates")
     public Result<Page<TaskTemplate>> getTaskTemplates(@RequestBody Map<String, Object> params) {