fix phase3 acceptance roots and payable validation

firstleg/src/test/java/com/baiyue/firstleg/repository/PdaSplitSettlementSqlContractTest.java

@@ -10,10 +10,33 @@ import org.junit.jupiter.api.Test;
 import org.springframework.core.io.ClassPathResource;
 
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 class PdaSplitSettlementSqlContractTest {
+    @Test
+    void addsPreloadConfirmationAuditColumnsForIncrementalPdaAllocation() throws Exception {
+        String moduleSql = new ClassPathResource("db/phase3-split-preload-schema.sql")
+            .getContentAsString(StandardCharsets.UTF_8);
+        String unifiedSql = Files.readString(Path.of("..", "deploy", "sql", "头程数据库统一增量-MySQL8.sql"),
+            StandardCharsets.UTF_8);
+
+        assertThat(moduleSql)
+            .contains("confirmed_by BIGINT UNSIGNED NULL")
+            .contains("confirmed_by_name VARCHAR(64) NULL")
+            .contains("confirmed_at DATETIME(3) NULL")
+            .contains("phase3_split_add_column('fl_preload_plan', 'confirmed_by'")
+            .contains("phase3_split_add_column('fl_preload_plan', 'confirmed_by_name'")
+            .contains("phase3_split_add_column('fl_preload_plan', 'confirmed_at'");
+        assertThat(unifiedSql)
+            .contains("CREATE PROCEDURE migrate_preload_confirmation_columns()")
+            .contains("ADD COLUMN confirmed_by BIGINT UNSIGNED NULL")
+            .contains("ADD COLUMN confirmed_by_name VARCHAR(64) NULL")
+            .contains("ADD COLUMN confirmed_at DATETIME(3) NULL");
+    }
+
     @Test
     void protectsLoadedAndRemainderSettlement() throws Exception {
         String sql = new ClassPathResource("db/phase3-inbound-parent-child-schema.sql")

firstleg/src/test/java/com/baiyue/firstleg/service/FeePaymentSnapshotValidatorTest.java

@@ -37,6 +37,14 @@ class FeePaymentSnapshotValidatorTest {
             .isInstanceOf(BizException.class).hasMessageContaining("账期应付不得");
     }
 
+    @Test
+    void payableWithoutSettlementModeReturnsBusinessValidationInsteadOfNullPointer() {
+        assertThatThrownBy(() -> validator.validate(9L, "PAYABLE", null,
+            null, null, null, null))
+            .isInstanceOf(BizException.class)
+            .hasMessageContaining("应付费用必须选择ON_ACCOUNT或DIRECT_PAID");
+    }
+
     @Test
     void directPaidRequiresTimeMethodAndReferenceOrVoucher() {
         LocalDateTime paidAt = LocalDateTime.of(2026, 8, 20, 10, 0);