Session seq is raw epoch millis; duration is masked with Math.abs

Audit finding C2 — theoretical, LOW-MEDIUM.

Session uses raw epoch millis for seq and Math.abs for duration (sentry/src/main/java/io/sentry/Session.java):

• seq is set from getSequenceTimestamp(), which returns timestamp.getTime() (raw epoch millis) — Session.java:309, invoked from the session-update path at :227. A backward clock step between updates → the newer update has a smaller seq → the server can discard the latest session state (lost end/error counts).
• calculateDurationTime uses Math.abs``(timestamp.getTime() - started.getTime()) (Session.java:240), which masks negative durations rather than surfacing them.

Source: JAVA-557 §C2.

閱讀 sentry/src/main/java/io/sentry/Session.java，特別查看第 227 行附近的 session 更新路徑、第 240 行附近的 calculateDurationTime，以及第 309 行附近的 getSequenceTimestamp。追蹤時鐘變更如何影響 sequence 排序與 duration 處理，然後找出相關的現有測試或測試入口。完成的標準是：在處理報告中的 clock-step 情況時，不會遺失較新的 session state，也不會掩蓋負 duration。