feat(db): mesh data model — meshes, members, invites, audit log

- pgSchema "mesh" with 4 tables isolating the peer mesh domain
- Enums: visibility, transport, tier, role
- audit_log is metadata-only (E2E encryption enforced at broker/client)
- Cascade on mesh delete, soft-delete via archivedAt/revokedAt

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/db/src/schema/credit-transaction.ts

@@ -0,0 +1,45 @@
+import { relations } from "drizzle-orm";
+import { integer, pgEnum, pgTable, text, timestamp } from "drizzle-orm/pg-core";
+
+import { generateId } from "@turbostarter/shared/utils";
+
+import { customer } from "./customer";
+
+export const creditTransactionTypeEnum = pgEnum("credit_transaction_type", [
+  "signup", // Initial free credits
+  "purchase", // Bought via billing
+  "usage", // Consumed by AI features
+  "admin_grant", // Manually added by admin
+  "admin_deduct", // Manually removed by admin
+  "refund", // Refunded credits
+  "promo", // Promotional credits
+  "referral", // Referral bonus
+  "expiry", // Credits expired
+]);
+
+export const creditTransaction = pgTable("credit_transaction", {
+  id: text().primaryKey().$defaultFn(generateId),
+  customerId: text("customer_id")
+    .notNull()
+    .references(() => customer.id, { onDelete: "cascade" }),
+  amount: integer().notNull(), // Positive = add, Negative = deduct
+  type: creditTransactionTypeEnum().notNull(),
+  reason: text(), // Human-readable description
+  metadata: text(), // JSON for additional context (e.g., AI feature used)
+  balanceAfter: integer("balance_after").notNull(), // Snapshot for reconciliation
+  createdAt: timestamp("created_at").notNull().defaultNow(),
+  createdBy: text("created_by"), // User ID who initiated (for admin actions)
+});
+
+export const creditTransactionRelations = relations(
+  creditTransaction,
+  ({ one }) => ({
+    customer: one(customer, {
+      fields: [creditTransaction.customerId],
+      references: [customer.id],
+    }),
+  }),
+);
+
+export type CreditTransaction = typeof creditTransaction.$inferSelect;
+export type InsertCreditTransaction = typeof creditTransaction.$inferInsert;