[thomasjm]

• mount9p-fuse now exits once unmounted even if its stdin stays open. Before, tokio waited at shutdown for the thread reading stdin. The library's mount() docs note the same pitfall.
• Test harness:
  • If a mount's FUSE session is still running 5s after unmounting, abort its connection instead of hanging. A process that copies the mount namespace while a test mount is up (a nix build sandbox, a container, unshare -m) keeps the filesystem alive after fusermount3 -u succeeds. Reproduced by running the tests alongside a sandboxed nix build.
  • Wait for diod to accept connections: it logs "Listening on" after bind but before listen, so an early connect could be refused.