Summary

The recursive file watcher (src/sidecar/file-watcher.ts) is meant to ignore changes deeper than 2 path levels (comment: "Limit depth to 1 (direct children + 1 level of subdirectories)"). It computes depth by splitting a path.relative() result on the literal '/':

const rel = relative(watch.path, filePath)
const depth = rel.split('/').length
if (depth > 2) return

On Windows, path.relative() returns backslash-separated paths (a\b\c\deep.txt), so split('/') returns a single-element array → depth is always 1 → depth > 2 never fires. The depth limit is completely inert on Windows, so deeply-nested file changes trigger Claude Code actions the code intends to suppress.

Fix

Extract the depth computation into a small helper that splits on either separator (identical behavior on POSIX, correct on Windows), and reuse it in the watcher:

function watchRelativeDepth(watchPath: string, filePath: string): number {
  return relative(watchPath, filePath).split(/[/\]/).length
}

-      if (isDir) {
-        const rel = relative(watch.path, filePath)
-        const depth = rel.split('/').length
-        if (depth > 2) return
-      }
+      if (isDir && watchRelativeDepth(watch.path, filePath) > 2) return

watchRelativeDepth is exposed via the existing _testing export.

Testing

Added a watchRelativeDepth block to src/sidecar/__tests__/file-watcher.test.ts using path.join (OS-native separators):

• direct child → depth 1; 1–2 levels → not skipped; 3–4 levels → skipped.

Verified on Windows: with the old split('/'), every path reports depth 1 so the 3- and 4-level cases are wrongly not skipped (test fails); with the fix they report depth 3/4 and are skipped (test passes). POSIX behavior is unchanged (/ paths split identically).