feat(seats): accounts without a 5-hour limit

Anthropic is removing the 5-hour limit in stages (from 2026-10-31), and
an account without it reports the weekly window alone. Until now the pool
took such an account for an unprobed seat: always eligible, ranked after
every other, never held to the weekly cutoff, with no cap on its passes.

- The burst window is the 5-hour one, else the weekly one
  (Seats::BurstWindow). An account whose burst window is the weekly one is
  ranked by it and admitted under the 95 % cutoff with the passes in
  flight projected on it, at the measured share per pass (0.04 at xhigh,
  0.125 otherwise; REVIEW_GATES_LENS_COST_7D_PCT), and waits for the weekly
  reset when over it.
- Every OAuth account and the local login takes at most 128 passes at once,
  every driver's counted (REVIEW_GATES_OAUTH_CONCURRENCY): every run
  measured with 149 or more in flight on one account drew usage-limit
  rejections, none of the 119 with 139 or fewer.
- A 'concurrents' rejection pauses the seat for 20 s or its retry-after,
  not until a window's reset (a seat sat two hours at 10 % on one).
- Board entries, the folded foreign record and the board's view carry
  cost7d, so the drivers see each other's weekly load.
- `seats` and the log table say `no limit` in such an account's 5-hour
  column; the board's others-line names its weekly projection.

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

tests/Seats/main.cpp

@@ -153,6 +153,15 @@ int main() {
     r = RenderStatusReport({MergeFableProbe(revoked, revoked)}, cfg, now, utc);
     Eq(r.contains("not usable: seat 3 invalid (token revoked)"), true);
     Eq(r.contains("fable probe:"), false);
+    // 2026-10-31: an account whose 5-hour limit is removed reports the weekly
+    // window alone - `no limit` in its 5h cell, the weekly window its burst
+    // window, ranked by it.
+    const Json nf = {{"seat", 3}, {"state", "ok"}, {"windows", {{"seven_day", {{"utilization", 3}, {"resetsAt", nowS + 6 * 86400}}}}}, {"util", 5}, {"binding", "seven_day"}, {"resetsAt", nowS + 6 * 86400}};
+    r = RenderStatusReport({seat(2, 61, 18), nf}, cfg, now, utc);
+    Eq(Lines(r).at(3), std::string("| 3    | no limit | —                 | 3%  | Sun 13 Sept, 10:00 (in 6d 0h) | —        |"));
+    Eq(Lines(r).at(6), std::string("eligible now: seat 3 (80% headroom), seat 2 (25% headroom) → next lens: seat 3"));
+    Eq(BurstWindow(nf.at("windows")) == "seven_day" && BurstWindow(seat(2, 61).at("windows")) == "five_hour" && !BurstWindow(Json::object()), true);
+    Eq(std::format("{}|{}|{}", WindowCell(nf.at("windows"), "five_hour"), WindowCell(Json::object(), "five_hour"), WindowCell(nf.at("windows"), "seven_day")), std::string("no limit|—|3%"));
     // The local login is seat 0, named `local`.
     r = RenderStatusReport({seat(0, 30), seat(2, 50)}, cfg, now, utc);
     Eq(Lines(r).at(2).starts_with("| local | 30%"), true);