Add honest accounting and automatic refund mechanism for completed jobs

Implement honest accounting post-job completion, calculating actual costs, adding margin, and enabling automatic refunds for overpayments via a new endpoint.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 418bf6f8-212b-4bb0-a7a5-8231a061da4e
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lib/db/src/schema/jobs.ts

@@ -36,6 +36,12 @@ export const jobs = pgTable("jobs", {
   actualOutputTokens: integer("actual_output_tokens"),
   actualCostUsd: real("actual_cost_usd"),
 
+  // ── Post-work honest accounting & refund ─────────────────────────────────
+  actualAmountSats: integer("actual_amount_sats"),
+  refundAmountSats: integer("refund_amount_sats"),
+  refundState: text("refund_state").$type<"not_applicable" | "pending" | "paid">(),
+  refundPaymentHash: text("refund_payment_hash"),
+
   createdAt: timestamp("created_at", { withTimezone: true }).defaultNow().notNull(),
   updatedAt: timestamp("updated_at", { withTimezone: true }).defaultNow().notNull(),
 });