feat: let the operator set the daily comment limit per account

The allowance was derived from the adaptive trust level with no way to
change it, which made the dashboard's "1 / 2 today" unexplainable and
left no way to slow an account down or push one along.

`dailyLimit` is null by default, keeping today's adaptive behaviour. A
whole number between 1 and 50 overrides it and is enforced verbatim in
either direction — it can raise an account above what it has earned or
hold it below. The trust level keeps being tracked underneath and is
reported as `adaptiveAllowance`, so the earned figure stays visible next
to the override, and clearing the field hands pacing back to the ladder.

Raising the limit above the earned allowance does remove the adaptive
backoff after a bad comment, so the dashboard says exactly that where the
limit is set. It does not touch the pause on two consecutive removals, a
comment the public cannot see, or a captcha challenge: those are safety
stops rather than rate controls and no limit setting can disable them.

Also correct two things the page was saying badly. The allowance is now
labelled "used in last 24h" with the trust level shown as what it earns,
because it is a rolling window and not a midnight reset. And a
per-community cap above the account allowance now states how much of it
is actually reachable — "1 of 10 today" beside an account limit of 2 read
as far more headroom than existed, since caps distribute the allowance
rather than adding to it.

Verified against a local instance: override above and below the earned
allowance, unrelated saves preserving it, clearing it through the UI,
rejection of 0/51/2.5/non-numeric, and a limit failing to clear a pause.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/product-and-safety.md

@@ -62,7 +62,7 @@ This is inauthentic account activity under Reddit's content policy, and many sub
 - Disabled by default, per account, and never inferred from any other setting.
 - Comments post without operator review, so both screening stages fail closed. The deterministic gate rejects links, contact solicitation, user tags, low-effort filler, and any text that reveals the generator or narrates the task. The second-stage classifier must actively approve with sufficient confidence; an outage stalls growth rather than publishing unreviewed text.
 - Thread text is attacker-controlled and is passed to the model only as fenced untrusted data. Reddit posts do contain text aimed at automated readers.
-- The daily allowance is adaptive, not configured: it starts at two comments per day and only rises while comments demonstrably survive and earn upvotes. A removal or a heavily downvoted comment lowers it immediately.
+- The daily allowance is adaptive by default: it starts at two comments per day and only rises while comments demonstrably survive and earn upvotes, and a removal or a heavily downvoted comment lowers it immediately. An operator may override the figure per account; doing so replaces the adaptive backoff but not the pause below, and the dashboard states that trade-off where the limit is set.
 - Two consecutive removals, a comment invisible to signed-out visitors, or a captcha challenge pauses the account until an operator clears it. A failed visibility probe proves nothing and never pauses anything.
 - One comment per thread across every owned account, a per-community daily cap, quiet hours, and jittered spacing.
 - Reddit's own refusals are authoritative: a community ban disables that community for that account, a throttle backs off at the scope Reddit named, and a signed-out response invalidates the session rather than being retried.