docs(acm2-75): 按需求与架构收口契约和规范

补齐接口契约的入站、Redis 与出站边界，规范对齐已定语义并作废过期条款；Kafka 生产端约束编号改为 D2。

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

src/test/kotlin/com/gzzn/omms/msgexchange/config/KafkaD3CheckTest.kt

@@ -7,12 +7,12 @@ import org.junit.jupiter.api.Test
 class KafkaD3CheckTest {
 
     @Test
-    fun `default config satisfies D3`() {
+    fun `default config satisfies D2`() {
         assertDoesNotThrow { KafkaD3Check(acks = "all", idempotence = "true", maxInFlight = "1") }
     }
 
     @Test
-    fun `acks=-1 also satisfies D3`() {
+    fun `acks=-1 also satisfies D2`() {
         assertDoesNotThrow { KafkaD3Check(acks = "-1", idempotence = "true", maxInFlight = "1") }
     }