feat(validations): merchant (bar/lavazh) ticket validations end-to-end

In-park merchants discharge customers' parking: a merchant user scans the
ticket on their device (/validate; validation:create + program↔user binding)
and applies their program — comp / first-N-minutes free / amount-off (capped,
typed at scan) / percent. All money stays at the booth: the quote folds live
validations in a canonical order (timeCredit → percent → fixed → comp, net
floors at 0, Σ lines ≡ gross − net), the payment records gross/discount and
CONSUMES the validation ids (an overstay's fresh period never re-applies
them), the receipt prints the gross → lines → net story, and the Z/X-report
carries discountTotalMinor leakage. Every apply/void is a signed, attributed
ledger event (refId = append-only void); program config is /setup/site master
data (Bar/Lavazh checkboxes + right-column panel, tabs when both) whose saves
sign config_change. Migration 0024 + reset-db drift-guard entries; 8 route
integration tests + priceSession fold suite.

See wiki/concepts/validation-discounts.md for the full design record.

Claude-Session: https://claude.ai/code/session_01YYkpEsLmoQPaize5ec3oUm

apps/server/src/booth-print.ts

@@ -80,6 +80,8 @@ function receiptFigures(
     currency?: string;
     tender?: "cash" | "card";
     graceExitMin?: number;
+    grossMinor?: number;
+    validationLines?: { label: string; discountMinor: number }[];
   };
   return {
     ticketId,
@@ -89,6 +91,9 @@ function receiptFigures(
     currency: p.currency ?? "ALL",
     tender: p.tender === "card" ? "card" : "cash",
     graceExitMin: typeof p.graceExitMin === "number" ? p.graceExitMin : null,
+    // Merchant validations, as settled on the signed payment (gross → lines → net).
+    grossMinor: typeof p.grossMinor === "number" ? p.grossMinor : null,
+    validationLines: Array.isArray(p.validationLines) ? p.validationLines : undefined,
   };
 }