fix(react-agent-core): widen ModelSpec.resolve to public

resolve() is the framework SPI: ReActAgentComponent (in a different
package) needs to call spec.resolve(cfg), which protected access
does not permit. The test's TestSpec override is widened in lockstep
since Java forbids narrowing visibility on override.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

liteflow-react-agent/liteflow-react-agent-core/src/main/java/com/yomahub/liteflow/agent/model/ModelSpec.java

@@ -48,6 +48,9 @@ public abstract class ModelSpec<SELF extends ModelSpec<SELF>> {
      * 把本描述符解析为 agentscope {@link Model} 实例。
      * 实现需从 {@link AgentConfig} 中读取对应平台的 credential，
      * 并把共性 + 个性参数翻译成 agentscope 的 GenerateOptions。
+     * <p>
+     * 本方法是框架 SPI：{@code ReActAgentComponent} 在不同包中调用，
+     * 因此必须为 {@code public}。
      */
-    protected abstract Model resolve(AgentConfig cfg);
+    public abstract Model resolve(AgentConfig cfg);
 }

liteflow-testcase-el/liteflow-testcase-el-react-agent/src/test/java/com/yomahub/liteflow/agent/model/ModelSpecTest.java

@@ -10,7 +10,7 @@ class ModelSpecTest {
 
     /** 仅用于测试的最小 ModelSpec 子类。 */
     static class TestSpec extends ModelSpec<TestSpec> {
-        @Override protected Model resolve(AgentConfig cfg) { return null; }
+        @Override public Model resolve(AgentConfig cfg) { return null; }
     }
 
     @Test