Add Products/Catalog module (MVP): migration, repository, API

Ports the legacy products table's core shape (eden.md §2 §1.1, Master
Prompt §6.3) faithfully but MVP-scoped: product_code sequence, the 5 fixed
price tiers (price_0/12/24/36/48), impl_unit_price, and stock/serial/
asset-tag/MAC tracking flags. Leaves out legacy telecom-billing specifics
(service_type, metered, tariff_rates, ixc_product_code) for a later phase.

Mirrors the Companies module's structure and conventions exactly: COALESCE
partial updates, JwtAuthGuard/PermissionGuard with open read / gated write
(products:edit) per ADR-0004, product.created/product.updated audit events.
Money fields are validated as non-negative NUMERIC in the DTO only — no
pricing/calculation logic here, that belongs to the future Quotes phase.

Does not touch apps/api/src/app.module.ts or packages/database/src/index.ts
(wiring is left to integration) to avoid conflicting with sibling agents'
concurrent edits to those files; the ProductsService deep-imports the
repository module directly instead of via the shared barrel, noted in a
code comment.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

packages/database/migrations/1788438907074_products.cjs

@@ -0,0 +1,68 @@
+/**
+ * Commercial bounded context, first slice: products (sellable catalog
+ * items) — Master Prompt §6.3, eden.md §2 §1.1. MVP scope only: the shape
+ * below ports the legacy `products` table's core identity/pricing/flag
+ * columns faithfully (product_code sequence, the 5 fixed price tiers,
+ * impl_unit_price), but deliberately leaves out service_type/metered/
+ * tariff_rates/ixc_product_code — those are legacy telecom-billing
+ * specifics that belong to a later phase, not invented here. `product_type`
+ * is free text for now (no CHECK) since the enum of types isn't finalized;
+ * tightening it to a CHECK/lookup table is future work once Quotes needs
+ * to branch behavior on it.
+ *
+ * Quotes/pricing-tier selection logic is explicitly out of scope here —
+ * this migration only stores the data, it computes nothing.
+ */
+
+exports.shorthands = undefined;
+
+exports.up = (pgm) => {
+  pgm.sql(`
+    CREATE SEQUENCE products_product_code_seq START 1;
+
+    CREATE TABLE products (
+      id                 UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+      created_at         TIMESTAMPTZ NOT NULL DEFAULT now(),
+      updated_at         TIMESTAMPTZ NOT NULL DEFAULT now(),
+      created_by         UUID REFERENCES users(id),
+      product_code       INTEGER NOT NULL UNIQUE DEFAULT nextval('products_product_code_seq'),
+      name               TEXT NOT NULL,
+      description        TEXT,
+      product_type       TEXT NOT NULL,
+      product_group      TEXT,
+      product_subgroup   TEXT,
+      brand              TEXT,
+      unit               TEXT NOT NULL DEFAULT 'unidade',
+      active             BOOLEAN NOT NULL DEFAULT true,
+      discontinued       BOOLEAN NOT NULL DEFAULT false,
+      tracks_stock       BOOLEAN NOT NULL DEFAULT false,
+      tracks_serial      BOOLEAN NOT NULL DEFAULT false,
+      tracks_asset_tag   BOOLEAN NOT NULL DEFAULT false,
+      tracks_mac         BOOLEAN NOT NULL DEFAULT false,
+      price_0            NUMERIC(12,2),
+      price_12           NUMERIC(12,2),
+      price_24           NUMERIC(12,2),
+      price_36           NUMERIC(12,2),
+      price_48           NUMERIC(12,2),
+      impl_unit_price    NUMERIC(12,2) NOT NULL DEFAULT 0
+    );
+    COMMENT ON TABLE products IS
+      'Catálogo de produtos vendáveis — eden.md §2 §1.1, Master Prompt §6.3. product_code é a sequência legada (distinta do UUID); price_0/12/24/36/48 são as 5 faixas fixas de preço por período de fidelidade, não uma tabela relacionada. Leitura aberta a qualquer autenticado (catálogo precisa ser navegável por qualquer vendedor); escrita restrita à permissão products:edit.';
+    COMMENT ON COLUMN products.impl_unit_price IS
+      'Valor de implantação por unidade, multiplicado pela quantidade do item na oferta (fase futura — Quotes). NUMERIC sempre, nunca float.';
+
+    CREATE TRIGGER trg_products_updated_at BEFORE UPDATE ON products
+      FOR EACH ROW EXECUTE FUNCTION set_updated_at();
+
+    CREATE INDEX idx_products_active ON products(active);
+
+    ALTER SEQUENCE products_product_code_seq OWNED BY products.product_code;
+  `);
+};
+
+exports.down = (pgm) => {
+  pgm.sql(`
+    DROP TABLE IF EXISTS products;
+    DROP SEQUENCE IF EXISTS products_product_code_seq;
+  `);
+};