Quotas: reset one address, or give some back

POST /rules/{ref}/reset-quota takes an optional address (one entry of a
per-address quota starts again) and give (bytes taken off what was used,
one address's or everyone's, until the next reset). The firewall keeps
the adjustment for its next apply, which writes the new usage into the
ruleset; housecarld applies at once and saves the usage. hc rule
reset-quota --address/--give; Reset and Give back in the web UI, per
address in the usage dialog.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/operations.md

@@ -161,7 +161,8 @@ start again. A disabled rule keeps its count for when it is enabled.
 ## Quotas
 
 `hc quotas` (and the rules page) show what each quota used and when it
-resets; `hc rule reset-quota ID` starts one again. housecarld resets
+resets; `hc rule reset-quota ID` starts one again (`--address` one device's,
+`--give 5gbytes` a top-up until the next reset). housecarld resets
 quotas at midnight when their period ends (late, if it was stopped then),
 and saves their usage every five minutes and when it stops; after a
 reboot it puts it back. A reboot without a clean stop loses at most the