- copied_file: check the read policy on the real path when it is
valid UTF-8; skip non-UTF-8 paths while automation roots are
active instead of checking a lossy name (path traversal via
symlink, CodeRabbit #3872 thread 1).
- full_bytes_cached: collect matching cache candidates under the
FULL lock, then run the read checks after releasing it, so
filesystem walks no longer stall other FULL users (thread 2).