docs: add IDEA shadow deployment and rollback guide

ruoyi-admin/src/main/resources/application.yml

@@ -178,3 +178,15 @@ xss:
 mybatis-plus:
   configuration:
     log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
+
+# 影子算法默认关闭；现场测试仅通过 IDEA 环境变量显式开启
+fortucky:
+  shadow:
+    enabled: ${FORTUCKY_SHADOW_ENABLED:false}
+    warehouse-id: ${FORTUCKY_SHADOW_WAREHOUSE_ID:}
+    timeout-seconds: ${FORTUCKY_SHADOW_TIMEOUT_SECONDS:3}
+  algorithm:
+    mode: ${FORTUCKY_ALGORITHM_MODE:SHADOW}
+    warehouse-id: ${FORTUCKY_ALGORITHM_WAREHOUSE_ID:01}
+    database-writes-enabled: ${FORTUCKY_ALGORITHM_DATABASE_WRITES_ENABLED:true}
+    legacy-fallback-on-technical-error: ${FORTUCKY_ALGORITHM_LEGACY_FALLBACK_ON_TECHNICAL_ERROR:false}

ruoyi-admin/src/test/java/com/ruoyi/algorithm/shadow/ShadowConfigurationTest.java

@@ -0,0 +1,60 @@
+package com.ruoyi.algorithm.shadow;
+
+import com.ruoyi.algorithm.integration.AlgorithmProperties;
+import com.ruoyi.algorithm.integration.SchedulingMode;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.context.properties.bind.Bindable;
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.boot.env.YamlPropertySourceLoader;
+import org.springframework.core.env.MutablePropertySources;
+import org.springframework.core.env.PropertySource;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.mock.env.MockEnvironment;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ShadowConfigurationTest {
+
+    @Test
+    void applicationDefaultsKeepShadowDisabledAndReadyForExplicitShadowEnablement() throws IOException {
+        MockEnvironment environment = new MockEnvironment();
+        Binder binder = applicationBinder(environment);
+
+        ShadowObservationProperties shadow = binder
+                .bind("fortucky.shadow", Bindable.of(ShadowObservationProperties.class))
+                .orElseThrow(() -> new IllegalStateException("fortucky.shadow configuration is missing"));
+        AlgorithmProperties algorithm = binder
+                .bind("fortucky.algorithm", Bindable.of(AlgorithmProperties.class))
+                .orElseThrow(() -> new IllegalStateException("fortucky.algorithm configuration is missing"));
+
+        assertThat(shadow.isEnabled()).isFalse();
+        assertThat(shadow.getWarehouseId()).isEmpty();
+        assertThat(shadow.getTimeoutSeconds()).isEqualTo(3);
+        assertThat(algorithm.getMode()).isEqualTo(SchedulingMode.SHADOW);
+        assertThat(algorithm.isDatabaseWritesEnabled()).isTrue();
+        assertThat(algorithm.getWarehouseId()).isEqualTo("01");
+    }
+
+    @Test
+    void standardLegacyFallbackEnvironmentVariableOverridesTheSafeDefault() throws IOException {
+        MockEnvironment environment = new MockEnvironment()
+                .withProperty("FORTUCKY_ALGORITHM_LEGACY_FALLBACK_ON_TECHNICAL_ERROR", "true");
+
+        AlgorithmProperties algorithm = applicationBinder(environment)
+                .bind("fortucky.algorithm", Bindable.of(AlgorithmProperties.class))
+                .orElseThrow(() -> new IllegalStateException("fortucky.algorithm configuration is missing"));
+
+        assertThat(algorithm.isLegacyFallbackOnTechnicalError()).isTrue();
+    }
+
+    private Binder applicationBinder(MockEnvironment environment) throws IOException {
+        MutablePropertySources propertySources = environment.getPropertySources();
+        List<PropertySource<?>> yaml = new YamlPropertySourceLoader()
+                .load("application", new ClassPathResource("application.yml"));
+        yaml.forEach(propertySources::addLast);
+        return Binder.get(environment);
+    }
+}