filesystem: search_files silently skips a subdirectory it cannot read #5189

Problem

In searchFilesWithValidation (src/filesystem/lib.ts), one try { … } catch { continue; } wraps the per-entry path validation, the match and the recursive descent. The catch is there to skip entries that resolve outside the allowed directories, but it also discards I/O errors such as EACCES from reading a subdirectory. search_files then returns a short result with no sign that it is incomplete, while directory_tree and list_directory report the same failure as an error.

Expected

Only validation failures are skipped silently. An error while walking is either reported, or the result states that it is partial; which of the two is a maintainer's call.

Prior work

• fix(filesystem): let a search_files read failure reach the caller #4910 by @feiiiiii5

The PR(s) above targeted the pre-refactor code and are closed as part of the backlog triage in #4875; this issue is where the work continues, with the PR(s) as a prototype. Thank you to their authors.