Review follow-up: normalizePath strips a trailing slash, but the slash is
semantic for legacy-scope changes — filepath.Dir("/x/Show/") is the
directory itself while filepath.Dir("/x/Show") is its parent, so dropping
it widened targeted directory notifications into parent/library scans.
applyRewrites now records whether the incoming path ended with a separator
(either form) and restores it on the returned path.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
