Extract call-site and link policy helpers to clarify analysis pipeline rules.

Move functional-interface checks, cross-frame Supplier resolution, and transition link resolution into dedicated types so call graph and linker share one DRY implementation.

Co-authored-by: Cursor <cursoragent@cursor.com>

state_machine_exporter/src/test/java/click/kamil/springstatemachineexporter/analysis/enricher/CallChainLinkPolicyTest.java

@@ -0,0 +1,36 @@
+package click.kamil.springstatemachineexporter.analysis.enricher;
+
+import click.kamil.springstatemachineexporter.analysis.model.LinkResolution;
+import click.kamil.springstatemachineexporter.analysis.model.TriggerPoint;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class CallChainLinkPolicyTest {
+
+    @Test
+    void shouldFailClosedOnEnumSetAmbiguousWiden() {
+        TriggerPoint trigger = TriggerPoint.builder()
+                .ambiguous(true)
+                .event("ENUM_SET:com.example.OrderEvent.PAY,com.example.OrderEvent.SHIP")
+                .polymorphicEvents(List.of("com.example.OrderEvent.PAY", "com.example.OrderEvent.SHIP"))
+                .build();
+
+        assertThat(CallChainLinkPolicy.shouldFailClosedOnAmbiguousCallGraphWiden(trigger)).isTrue();
+        assertThat(CallChainLinkPolicy.resolveLinkResolution(trigger, List.of(), false))
+                .isEqualTo(LinkResolution.AMBIGUOUS_WIDEN);
+    }
+
+    @Test
+    void shouldMarkExternalTriggersUnresolved() {
+        TriggerPoint trigger = TriggerPoint.builder()
+                .external(true)
+                .event("eventString")
+                .build();
+
+        assertThat(CallChainLinkPolicy.resolveLinkResolution(trigger, List.of(), false))
+                .isEqualTo(LinkResolution.UNRESOLVED_EXTERNAL);
+    }
+}

state_machine_exporter/src/test/java/click/kamil/springstatemachineexporter/analysis/service/FunctionalInterfaceTypesTest.java

@@ -0,0 +1,28 @@
+package click.kamil.springstatemachineexporter.analysis.service;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class FunctionalInterfaceTypesTest {
+
+    @Test
+    void shouldRecognizeSupplierParameter() {
+        assertThat(FunctionalInterfaceTypes.isFunctionalInterface("java.util.function.Supplier"))
+                .isTrue();
+    }
+
+    @Test
+    void shouldAcceptLambdaIntoSupplierParameter() {
+        assertThat(FunctionalInterfaceTypes.isProvablyResolvedCallSiteArgument(
+                "() -> OrderEvent.CANCEL", "java.util.function.Supplier"))
+                .isTrue();
+    }
+
+    @Test
+    void shouldRejectNonFunctionalParameter() {
+        assertThat(FunctionalInterfaceTypes.isProvablyResolvedCallSiteArgument(
+                "OrderEvent.CANCEL", "com.example.OrderEvent"))
+                .isFalse();
+    }
+}