feat: complete M3 runtime snapshot and profile save archive

server-rs/crates/shared-kernel/src/lib.rs

@@ -65,6 +65,11 @@ pub fn format_timestamp_micros(micros: i64) -> String {
     format!("{seconds}.{subsec_micros:06}Z")
 }
 
+/// 统一把 `OffsetDateTime` 转成 Unix 微秒时间戳，避免各模块重复手写纳秒除法。
+pub fn offset_datetime_to_unix_micros(value: OffsetDateTime) -> i64 {
+    (value.unix_timestamp_nanos() / 1_000) as i64
+}
+
 /// 统一格式化 RFC3339 字符串，避免每个模块自己拼格式化错误文案。
 pub fn format_rfc3339(value: OffsetDateTime) -> Result<String, String> {
     value
@@ -127,6 +132,15 @@ mod tests {
         );
     }
 
+    #[test]
+    fn offset_datetime_to_unix_micros_is_stable() {
+        let value = OffsetDateTime::UNIX_EPOCH
+            + time::Duration::seconds(1_713_686_401)
+            + time::Duration::microseconds(234_567);
+
+        assert_eq!(offset_datetime_to_unix_micros(value), 1_713_686_401_234_567);
+    }
+
     #[test]
     fn format_and_parse_rfc3339_round_trip() {
         let now = OffsetDateTime::UNIX_EPOCH + time::Duration::seconds(1_713_686_400);