test(integration): JDBC 集成测试 Testcontainers 兜底 + 全结构回环矩阵 (ACM2-29 P3-A)

- PgTestSupport 三级解析：MSGX_PG_* 显式环境变量 → Testcontainers 自动起
  postgres:17-alpine 隔离容器（JVM 单例复用，docker 不可用才跳过）→ assumeTrue
  绝不误报通过；解决了「本机端口被占/无库则集成测试静默跳过」的验收假绿问题
- loadCollections 只输出非空属性（缺失键语义），write→read 线格式一致
- 新增 readAfterWrite 矩阵用例：16 类结构（多行/重复资源号/非连续源序号/异常
  前缀列/文本旁列）persist → findNextStateByFlid 深度等值 + wire(nextState) ==
  wire(readAfterWrite) 双断言（评审 F5 持久化侧+线格式侧闭环）

验证：MSGX_PG_PORT=5433 外接库 108 用例全绿；无环境变量 Testcontainers
自动容器路径 18/18 全绿

src/main/kotlin/com/gzzn/omms/msgexchange/infra/persistence/jdbc/FlightDetailTables.kt

@@ -136,9 +136,11 @@ internal object FlightDetailTables {
                 "SELECT * FROM ${spec.table} WHERE flid = ? ORDER BY ordinal ASC",
                 { ps -> ps.setString(1, flid) },
             ) { rs ->
-                spec.columns.associate { (attr, col) -> attr to rs.getString(col) }.toMutableMap().apply {
-                    put(spec.seqAttr, rs.getString("source_seq"))
-                }
+                // 只输出非空属性（缺失键语义），保证 write→read 线格式一致（评审 F5）
+                spec.columns.associate { (attr, col) -> attr to rs.getString(col) }
+                    .filterValues { it != null }
+                    .toMutableMap()
+                    .apply { rs.getString("source_seq")?.let { put(spec.seqAttr, it) } }
             }
             if (rows.isNotEmpty()) {
                 out[spec.collectionKey] = mapper.writeValueAsString(rows)
@@ -149,12 +151,12 @@ internal object FlightDetailTables {
                 "SELECT source_seq, apcd, scat, scdt FROM flight_route_point WHERE flid = ? AND route_kind = ? ORDER BY ordinal ASC",
                 { ps -> ps.setString(1, flid); ps.setString(2, kind) },
             ) { rs ->
-                mapOf(
-                    "RTNO" to rs.getString("source_seq"),
-                    "APCD" to rs.getString("apcd"),
-                    "SCAT" to rs.getString("scat"),
-                    "SCDT" to rs.getString("scdt"),
-                )
+                buildMap {
+                    rs.getString("source_seq")?.let { put("RTNO", it) }
+                    rs.getString("apcd")?.let { put("APCD", it) }
+                    rs.getString("scat")?.let { put("SCAT", it) }
+                    rs.getString("scdt")?.let { put("SCDT", it) }
+                }
             }
             if (rows.isNotEmpty()) {
                 out[key] = mapper.writeValueAsString(rows)