* feat: add filemanager session and crypto version detection
* refactor: move copy logic into filemanager, remove fileutil dependency
* fix: apply review suggestions for filemanager
* feat: add Windows locked file tests, fix readFileContent with ReadFile+FileMapping fallback
* fix: remove self-PID skip in findFileHandle to fix Windows CI test
* fix: seek to file start before reading duplicated handle
* fix: use full path matching in findFileHandle to avoid cross-app handle collision
* test: enhance Windows copyLocked tests with write-then-read, large file, and normal copy scenarios
* fix: check all errors in Windows tests, use bytes.Equal for large file comparison
* fix: use stable path suffix matching to handle Windows short path names in CI