feat(seats): an API seat's cycle starts on its own grant day

The ledger reset every API seat's spend on one
REVIEW_GATES_API_CYCLE_DAY and cleared every credit-out, an OpenRouter
key's too, at that reset. Each API seat's cycle starts on its
ANTHROPIC_API_KEY<n>_GRANT_DAY now (1..31, a day past a month's end its
last), else the cycle day, also 1..31. A credit-out carries across the
rollover, and the run's probe tries a key held out on credit again, as
`seats` does an API key: an ok lifts the mark - an API key's is new
credits, its cycle restarting from the grant day, or from today when
that day is over a week back; an OpenRouter key keeps its cycle's spend,
and a key that answers with its cycle's budget spent stays out on that
budget. A probe that finds a key out of credit records it, unless the
ledger already has it out. Both are decided in one locked update on the
file's entry, a mark another driver made since the probe started
standing, and the ledger's stamps carry their UTC offset so marks are
ordered by instant.

`seats` shows the probe's reading beside the driver's verdict (the
`probe` and `driver` columns replace `state` and `ledger: out`), each
seat's grant day and when its next credits are due, and notes on what
the probe changed in the ledger or why the driver's verdict stands; the
run logs the days.

interfaces/Crafter.Review-Seats.cppm

@@ -46,13 +46,18 @@ export namespace Crafter::Review::Seats {
     Json ConfigFromEnv(const std::map<std::string, std::string>& env);
     std::vector<std::pair<std::int32_t, std::string>> SeatTokensFromEnv(const std::map<std::string, std::string>& env);
     std::vector<std::pair<std::int32_t, std::string>> ApiKeysFromEnv(const std::map<std::string, std::string>& env);
+    // {n: day}: ANTHROPIC_API_KEY<n>_GRANT_DAY, the day of the month seat n's
+    // organization receives its plan's credits (the Console's
+    // Promotional-credits expiry minus three days), 1..31; anything else is
+    // ignored.
+    std::map<std::int32_t, std::int32_t> ApiGrantDays(const std::map<std::string, std::string>& env);
     std::vector<std::pair<std::int32_t, std::string>> OpenRouterKeysFromEnv(const std::map<std::string, std::string>& env);
     // Every `[export ]NAME=value` line of a dotenv text, in order: blanks
     // around the `=` and the value dropped, one pair of matching quotes
     // stripped; anything else skipped.
     std::vector<std::pair<std::string, std::string>> DotenvLines(std::string_view text);
     // Only the seat lines of those: the OAuth tokens, the numbered API keys
-    // and the OpenRouter keys; everything else ignored.
+    // with their grant days and the OpenRouter keys; everything else ignored.
     std::map<std::string, std::string> SeatTokensFromEnvFile(std::string_view text);
     // The REVIEW_GATES_* lines of a dotenv file (quotes and `export`
     // stripped). SeatPool::SettingsOf lays the placement settings among them
@@ -142,7 +147,11 @@ export namespace Crafter::Review::Seats {
     std::string RenderTable(const std::vector<std::vector<std::string>>& rows);
     std::string RenderStatusReport(const std::vector<Json>& seats, const Json& config, double now, const Zone& zone, const Json& board = nullptr,
                                    const std::map<std::int32_t, std::string>& keys = {});
-    std::string RenderApiReport(const std::vector<Json>& apiSeats, const Json& apiConfig, const Json& board = nullptr,
+    // API-credit seats: the probe's verdict beside the driver's (its ledger
+    // against the budget), the cycle, the grant day and when the next
+    // credits are due - each seat's ledger, ledgerOut, grantDay, nextCredits
+    // and the probe's ledger event as the seats command set them.
+    std::string RenderApiReport(const std::vector<Json>& apiSeats, const Json& apiConfig, double now, const Json& board = nullptr,
                                 const std::map<std::int32_t, std::string>& keys = {});
     std::string RenderDrivers(const Json& board, double now, const Zone& zone);
 }