[kbuffardi]

Summary

• reconcile open editor tabs after a successful terminal rm
• close tabs for descendants of recursively removed directories
• preserve existing runtime-delete tab behavior and leave failed deletion unchanged

Verification

• npm run lint
• npm run test:e2e
• npm run build

Closes #126

[kbuffardi]

Root-cause update after reproducing the reported behavior:

rm .DS_Store produced no error and left the file in both the Explorer and
host folder.

app.js supplied onRemove, but createTerminal() did not accept or assign it,
leaving the terminal's removal callback unset. Terminal rm therefore took an
optional-call no-op path. The PR now binds that callback, adds dotfile coverage,
and reports Filesystem unavailable rather than claiming success when the
service is absent.