feat: billing period for subscriptions, costs in redundancy analysis

lib/db/src/schema/tool-costs.ts

@@ -6,6 +6,7 @@ export const toolCostsTable = pgTable("tool_costs", {
   id: serial("id").primaryKey(),
   toolId: integer("tool_id").notNull().references(() => toolsTable.id, { onDelete: "cascade" }),
   licenseType: text("license_type", { enum: ["free", "subscription", "one_time", "usage_based"] }).notNull().default("free"),
+  billingPeriod: text("billing_period", { enum: ["monthly", "quarterly", "yearly"] }),
   cost: numeric("cost", { precision: 10, scale: 2 }),
   currency: text("currency").default("EUR"),
   renewalDate: timestamp("renewal_date", { withTimezone: true }),