fix(file_tools): normalize path separator before device-path blocklist compare (#69373)

[Enough1122]

Summary

_is_blocked_device_path() normalizes with os.path.normpath and compares against POSIX strings. On Windows, normpath("/dev/zero") returns "\dev\zero" (backslashes) which never matches the POSIX "/dev/zero". The same applies to the startswith("/proc/") checks. The entire device/fd/proc read-guard was a silent no-op on Windows, and read_file("/dev/zero") genuinely hung via Git Bash's MSYS /dev/zero emulation.

Fix

Add _normalize_for_blocklist() helper that converts to forward slashes after os.path.normpath, then use it in _is_blocked_device_path(). The fix is cross-platform (same code path on all platforms, no platform-specific branches).

Files touched

• tools/file_tools.py — add _normalize_for_blocklist() helper + one-line change in _is_blocked_device_path()
• tests/tools/test_file_read_guards.py — add TestWindowsBlocklistSeparatorNormalize with 4 regression tests

Test plan

cd /c/Users/admin/AppData/Local/hermes/hermes-agent
./venv/Scripts/python.exe -m pytest tests/tools/test_file_read_guards.py::TestWindowsBlocklistSeparatorNormalize -v
# 4 passed in 0.79s

What this does NOT do

• No change to the blocklist contents — only the comparison path
• No platform-specific branches — the fix is one-line normalization that works identically on all platforms
• No public API change

Fixes #69373. Refs #4427.

— written by Hermes Agent on behalf of @Enough1122

[Enough1122]

cc @teknium1 @alt-glitch — fix pushed for #69373.

Verification on head a597b9f9:

Check	Result
pytest tests/tools/test_file_read_guards.py::TestWindowsBlocklistSeparatorNormalize -v	✅ 4 passed in 0.79s
git diff --check	✅ clean
git diff --stat origin/main..HEAD	✅ 2 files, +47/-1

Implementation summary:

• _normalize_for_blocklist() helper in tools/file_tools.py — applies os.path.normpath then converts to forward slashes with .replace(os.sep, "/")
• One-line change in _is_blocked_device_path(): os.path.normpath(...) → _normalize_for_blocklist(...)
• 4 regression tests covering the fix

NOT doing: not changing the blocklist contents, not adding platform-specific branches, no public API change.

Ready for maintainer review.

— written by Hermes Agent on behalf of @Enough1122

[Enough1122]

Closing this stale PR for now: it has had no substantive human review/action and is unlikely to be merged in its current state. Reopen or submit a fresh PR if the issue remains relevant.