index/mount.js:175:pN-190 memoizes subsOf per root in a process-lifetime
SUBS map. Every neighbouring cache (TIPS, LANES, index/index.js:828:Mw)
keys on the BEE-048 fsw rev and drops on change; this one does not, and its
comment gives no reason for the exemption. In bee http or a resident pager
a submodule added or removed after the first mounts() stays invisible until
restart. Found in the 2026-08-21 review.
Key the memo on the rev like its neighbours. Repro: register a submodule under a live server; the mount map follows without a restart.