Third review:
- a broadcast counts once per recipient block, welcomes don't count
against block caps, and presence, cursor chat and pings have their own
per-address budget, so an office behind one address works together
- when everyone's reading budget runs out, the biggest readers are cut
off until it fits (their bytes freed at once), no cliff
- block counters are forgotten once only the table holds them
- install.sh: root's downloads, clone, swap file and built binary in a
root-only directory; the build user builds its own copy; the binary is
copied out with the build user's rights
- recommended open-mode settings in install.sh's config and the docs
d74eeb4ab3