Incus 7 on cgroup v2 writes memory.swap.max=0 for every container
unless limits.memory.swap carries an explicit byte amount (true/false
both end up as 0), so containers previously got no host swap at all
and `free` inside showed 0. Add incus.swap_ratio (default 0.5) so each
container gets limits.memory.swap = limits.memory x ratio, set at
create/reinstall and on quota changes.
- config: incus.swap_ratio field + registry entry (non-negative float,
0 disables swap; ApplyImmediate)
- lx: Client carries swapRatio; SetMem keeps swap proportional,
SetSwap refreshes only the swap key
- mgr: ApplySwapToAll refreshes every container from the DB memory
quota (idempotent, no restart)
- cli: `vps config set incus.swap_ratio N` re-applies to all
containers automatically; `vps swap-reapply` is the manual/repair
path for containers created before swap support
- docs: configuration/architecture/README updated
Co-authored-by: CommandCodeBot <noreply@commandcode.ai>
