fix(config): 指定 API_BASE_URL 时跳过地址探测

test/config/server_endpoint_test.dart

@@ -66,6 +66,59 @@ void main() {
     expect(AppConfig.devHostBaseUrl, 'http://192.168.31.187:8081');
   });
 
+  test('should_skip_probe_when_compiled_override_is_set', () async {
+    const compiled = 'http://compiled.test:8081';
+    var probeCalls = 0;
+
+    await AppConfig.probeAndApplyBaseUrl(
+      compiledOverride: compiled,
+      probe: (_) async {
+        probeCalls++;
+        return true;
+      },
+    );
+
+    expect(probeCalls, 0);
+    expect(AppConfig.apiBaseUrl, compiled);
+  });
+
+  test('should_keep_runtime_endpoint_when_compiled_override_is_set', () async {
+    const runtime = 'http://runtime.test:8081';
+    const compiled = 'http://compiled.test:8081';
+    var probeCalls = 0;
+    AppConfig.applyRuntimeBaseUrl(runtime);
+
+    await AppConfig.probeAndApplyBaseUrl(
+      compiledOverride: compiled,
+      probe: (_) async {
+        probeCalls++;
+        return true;
+      },
+    );
+
+    expect(probeCalls, 0);
+    expect(AppConfig.apiBaseUrl, runtime);
+  });
+
+  test('should_keep_probing_when_compiled_override_is_empty', () async {
+    final attempts = <String>[];
+
+    await AppConfig.probeAndApplyBaseUrl(
+      compiledOverride: '',
+      probe: (baseUrl) async {
+        attempts.add(baseUrl);
+        return baseUrl == AppConfig.publicBaseUrl;
+      },
+    );
+
+    expect(attempts, [
+      AppConfig.lanBaseUrl,
+      AppConfig.devHostBaseUrl,
+      AppConfig.publicBaseUrl,
+    ]);
+    expect(AppConfig.apiBaseUrl, AppConfig.publicBaseUrl);
+  });
+
   test(
     'should_probe_all_candidates_in_parallel_before_applying_priority',
     () async {