fix: restore miniapp public startup flows

backend/src/main/java/com/danyang/match/platform/activity/controller/ActivityController.java

@@ -25,7 +25,7 @@ public class ActivityController {
     @GetMapping
     public ApiResponse<?> getActivities(
             @AuthenticationPrincipal UserPrincipal principal) {
-        String userId = principal.id();
+        String userId = principal == null ? null : principal.id();
         return ApiResponse.ok(activityService.getActivities(userId));
     }
 

backend/src/main/java/com/danyang/match/platform/shared/config/SecurityConfig.java

@@ -42,6 +42,7 @@ public class SecurityConfig {
                         .requestMatchers("/auth/wechat/login", "/auth/refresh", "/auth/operator/login").permitAll()
                         .requestMatchers("/health/**").permitAll()
                         .requestMatchers("/version").permitAll()
+                        .requestMatchers("/app/config").permitAll()
                         .requestMatchers("/activities").permitAll()
                         .requestMatchers("/auth/**").authenticated()
                         // 操作台接口需要认证

backend/src/test/java/com/danyang/match/platform/security/PublicMiniappApiTest.java

@@ -0,0 +1,43 @@
+package com.danyang.match.platform.security;
+
+import com.danyang.match.platform.activity.service.ActivityService;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.List;
+
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc
+class PublicMiniappApiTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockBean
+    private ActivityService activityService;
+
+    @Test
+    void appConfigIsAvailableWithoutLogin() throws Exception {
+        mockMvc.perform(get("/api/v1/app/config").contextPath("/api/v1"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.success").value(true));
+    }
+
+    @Test
+    void activityListIsAvailableWithoutLogin() throws Exception {
+        when(activityService.getActivities(null)).thenReturn(List.of());
+
+        mockMvc.perform(get("/api/v1/activities").contextPath("/api/v1"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.success").value(true));
+    }
+}