refactor(config): drop system-time defaults from domain and entry points

删除会被误用的系统时间默认值：MsgEvent.createdAt、ProcState.updatedAt、InboxPoller.pollOnce(now)、HistorySweepJob.run(now)、Identity.of(day)。Identity 的日期边界改由 MessageProcessor 按 PARAM:msgx.operation-day.zone 算出后传入（边界关闭时身份值不变）；StubProcState/StubInbox 改注入 Clock（测试可传假时钟），全部调用点显式传时间。

验证：./gradlew test 145 tests / 0 fail / 0 skipped。

src/main/kotlin/com/gzzn/omms/msgexchange/infra/stub/StubRepositories.kt

@@ -30,6 +30,7 @@ import com.gzzn.omms.msgexchange.domain.SnapshotLogEntry
 import com.gzzn.omms.msgexchange.infra.persistence.SnapshotLogRepository
 import io.micronaut.context.annotation.Requires
 import jakarta.inject.Singleton
+import java.time.Clock
 import java.time.Instant
 import java.time.LocalDate
 import java.time.ZoneId
@@ -56,7 +57,7 @@ class StubPipelineLock : PipelineLockRepository {
 @Singleton
 @Requires(property = "msgx.stubs", value = "true")
 /** 内存版 PROC_STATE：入队幂等，写终态时一并写下回填待办。 */
-class StubProcState : ProcStateRepository {
+class StubProcState(private val clock: Clock = Clock.systemUTC()) : ProcStateRepository {
     val rows = linkedMapOf<Long, ProcState>()
     val bound = linkedMapOf<String, Long>()
 
@@ -74,6 +75,7 @@ class StubProcState : ProcStateRepository {
             msgId, ProcStatus.PENDING,
             receivedAt = receivedAt,
             enqueuedAt = enqueuedAt ?: receivedAt,
+            updatedAt = clock.instant(),
         )
         return true
     }
@@ -89,7 +91,7 @@ class StubProcState : ProcStateRepository {
         val owner = bound[identityKey]
         if (owner != null && owner != msgId) return false
         bound[identityKey] = msgId
-        rows[msgId] = (rows[msgId] ?: ProcState(msgId, ProcStatus.PENDING)).copy(identityKey = identityKey)
+        rows[msgId] = (rows[msgId] ?: ProcState(msgId, ProcStatus.PENDING, updatedAt = clock.instant())).copy(identityKey = identityKey)
         return true
     }
 
@@ -103,14 +105,14 @@ class StubProcState : ProcStateRepository {
         errorClass: ErrorClass?,
         lastError: String?,
     ) {
-        val old = rows[msgId] ?: ProcState(msgId, state)
+        val old = rows[msgId] ?: ProcState(msgId, state, updatedAt = clock.instant())
         rows[msgId] = old.copy(
             state = state,
             nextAttemptAt = nextAttemptAt ?: old.nextAttemptAt,
             attempts = attempts ?: old.attempts,
             errorClass = errorClass ?: old.errorClass,
             lastError = lastError ?: old.lastError,
-            updatedAt = Instant.now(),
+            updatedAt = clock.instant(),
         )
     }
 
@@ -123,7 +125,7 @@ class StubProcState : ProcStateRepository {
         attempts: Int?,
         now: Instant,
     ) {
-        val old = rows[msgId] ?: ProcState(msgId, state)
+        val old = rows[msgId] ?: ProcState(msgId, state, updatedAt = clock.instant())
         rows[msgId] = old.copy(
             state = state,
             errorClass = errorClass,
@@ -451,7 +453,7 @@ class StubReqTrack : ReqTrackRepository {
 @Singleton
 @Requires(property = "msgx.stubs", value = "true")
 /** 内存版共享信箱：可以模拟上游写入、库方清除，并记录哪些行被打上了处理标记。 */
-class StubInbox : CminmsgInboxRepository {
+class StubInbox(private val clock: Clock = Clock.systemUTC()) : CminmsgInboxRepository {
     val raws = linkedMapOf<Long, String>()
     private val received = linkedMapOf<Long, Instant>()
     private val marks = linkedMapOf<Long, String>()
@@ -464,7 +466,7 @@ class StubInbox : CminmsgInboxRepository {
     override fun insertRaw(rawXml: String): Long {
         val id = ids.incrementAndGet()
         raws[id] = rawXml
-        received[id] = Instant.now()
+        received[id] = clock.instant()
         return id
     }
 
@@ -497,7 +499,7 @@ class StubInbox : CminmsgInboxRepository {
     fun simulateExternalWrite(rawXml: String): Long = insertRaw(rawXml)
 
     /** 测试辅助：模拟先分配 ID、稍后才可见的迟提交行。 */
-    fun restoreRow(msgId: Long, rawXml: String, receivedAt: Instant = Instant.now()) {
+    fun restoreRow(msgId: Long, rawXml: String, receivedAt: Instant = clock.instant()) {
         raws[msgId] = rawXml
         received[msgId] = receivedAt
     }