feat(db): stock CHECK constraints + audit_logs DATETIME (2038 fix)

Migration 20260612234500: CHECK (quantity >= 0) on sklad_batches and
sklad_item_locations — the DB itself now rejects negative stock, so a
future C2-class bug (cumulative decrements driving a batch negative and
silently vanishing from totals) becomes a loud error instead of hidden
corruption. All three databases verified clean of negative rows before
the migration.

audit_logs.created_at TIMESTAMP(0) -> DATETIME(0): TIMESTAMP dies in 2038
and converts through the session timezone; existing wall times preserved
by the MODIFY.

Pinned by db-constraints.test.ts (4 tests, each watched fail pre-migration:
negative insert/update/location all succeeded before, 2098 audit timestamp
was rejected before).

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

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "app-ts",
-  "version": "2.4.32",
+  "version": "2.4.33",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "app-ts",
-      "version": "2.4.32",
+      "version": "2.4.33",
       "license": "ISC",
       "dependencies": {
         "@anthropic-ai/sdk": "^0.102.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "app-ts",
-  "version": "2.4.32",
+  "version": "2.4.33",
   "description": "",
   "main": "dist/server.js",
   "scripts": {

prisma/migrations/20260612234500_stock_checks_and_audit_datetime/migration.sql

@@ -0,0 +1,14 @@
+-- AlterTable
+ALTER TABLE `audit_logs` MODIFY `created_at` DATETIME(0) NULL DEFAULT CURRENT_TIMESTAMP(0);
+
+
+-- Stock invariants enforced by the database itself: a future cumulative-
+-- decrement bug (the C2 class — duplicate issue lines driving a batch
+-- negative and silently vanishing from stock totals) becomes a loud error
+-- instead of hidden corruption. All databases verified clean of negative
+-- rows before this migration (2026-06-12).
+ALTER TABLE `sklad_batches`
+  ADD CONSTRAINT `chk_sklad_batches_quantity_nonneg` CHECK (`quantity` >= 0);
+
+ALTER TABLE `sklad_item_locations`
+  ADD CONSTRAINT `chk_sklad_item_locations_quantity_nonneg` CHECK (`quantity` >= 0);

prisma/schema.prisma

@@ -65,7 +65,9 @@ model audit_logs {
   new_values  String?   @db.LongText
   user_agent  String?   @db.Text
   session_id  String?   @db.VarChar(128)
-  created_at  DateTime? @default(now()) @db.Timestamp(0)
+  // DATETIME, not TIMESTAMP — TIMESTAMP dies in 2038 and converts through
+  // the session timezone (2026-06-12 hardening migration).
+  created_at  DateTime? @default(now()) @db.DateTime(0)
 
   @@index([action], map: "idx_audit_logs_action")
   @@index([created_at], map: "idx_audit_logs_created")

src/__tests__/db-constraints.test.ts

@@ -0,0 +1,136 @@
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import prisma from "../config/database";
+
+/**
+ * Pins the 2026-06-12 DB hardening migration:
+ * 1. CHECK (quantity >= 0) on sklad_batches + sklad_item_locations — the DB
+ *    itself rejects negative stock, so a future C2-class bug (cumulative
+ *    decrements driving a batch negative) becomes a loud error instead of
+ *    silently hidden corruption.
+ * 2. audit_logs.created_at is DATETIME, not TIMESTAMP — no 2038 cap.
+ */
+
+const N = "db_constraints_";
+
+let itemId: number;
+let locationId: number;
+let receiptId: number;
+let lineAId: number;
+let lineBId: number;
+
+async function cleanup() {
+  await prisma.sklad_batches.deleteMany({
+    where: { item: { name: { contains: N } } },
+  });
+  await prisma.sklad_item_locations.deleteMany({
+    where: { item: { name: { contains: N } } },
+  });
+  await prisma.sklad_receipt_lines.deleteMany({
+    where: { item: { name: { contains: N } } },
+  });
+  await prisma.sklad_receipts.deleteMany({ where: { notes: { contains: N } } });
+  await prisma.sklad_items.deleteMany({ where: { name: { contains: N } } });
+  await prisma.sklad_locations.deleteMany({
+    where: { name: { contains: N } },
+  });
+  await prisma.audit_logs.deleteMany({
+    where: { description: { contains: N } },
+  });
+}
+
+beforeAll(async () => {
+  await cleanup();
+  const item = await prisma.sklad_items.create({
+    data: { name: `${N}item`, unit: "ks" },
+  });
+  itemId = item.id;
+  const location = await prisma.sklad_locations.create({
+    data: { code: `DBC${Date.now() % 100000}`, name: `${N}loc` },
+  });
+  locationId = location.id;
+  const receipt = await prisma.sklad_receipts.create({
+    data: { notes: `${N}receipt`, status: "CONFIRMED" },
+  });
+  receiptId = receipt.id;
+  const lineA = await prisma.sklad_receipt_lines.create({
+    data: {
+      receipt_id: receiptId,
+      item_id: itemId,
+      quantity: 5,
+      unit_price: 1,
+    },
+  });
+  lineAId = lineA.id;
+  const lineB = await prisma.sklad_receipt_lines.create({
+    data: {
+      receipt_id: receiptId,
+      item_id: itemId,
+      quantity: 5,
+      unit_price: 1,
+    },
+  });
+  lineBId = lineB.id;
+});
+
+afterAll(async () => {
+  await cleanup();
+  await prisma.$disconnect();
+});
+
+describe("stock CHECK constraints", () => {
+  it("rejects inserting a negative batch quantity", async () => {
+    await expect(
+      prisma.sklad_batches.create({
+        data: {
+          item_id: itemId,
+          receipt_line_id: lineAId,
+          quantity: -1,
+          original_qty: 5,
+          unit_price: 1,
+          is_consumed: false,
+        },
+      }),
+    ).rejects.toThrow();
+  });
+
+  it("rejects updating a batch quantity below zero", async () => {
+    const batch = await prisma.sklad_batches.create({
+      data: {
+        item_id: itemId,
+        receipt_line_id: lineBId,
+        quantity: 5,
+        original_qty: 5,
+        unit_price: 1,
+        is_consumed: false,
+      },
+    });
+    await expect(
+      prisma.$executeRaw`UPDATE sklad_batches SET quantity = -2 WHERE id = ${batch.id}`,
+    ).rejects.toThrow();
+    const fresh = await prisma.sklad_batches.findUnique({
+      where: { id: batch.id },
+    });
+    expect(Number(fresh?.quantity)).toBe(5);
+  });
+
+  it("rejects a negative item_location quantity", async () => {
+    await expect(
+      prisma.sklad_item_locations.create({
+        data: { item_id: itemId, location_id: locationId, quantity: -1 },
+      }),
+    ).rejects.toThrow();
+  });
+});
+
+describe("audit_logs.created_at has no 2038 cap", () => {
+  it("accepts a far-future timestamp (DATETIME, not TIMESTAMP)", async () => {
+    const row = await prisma.audit_logs.create({
+      data: {
+        action: "test",
+        description: `${N}future`,
+        created_at: new Date(Date.UTC(2098, 0, 15, 12, 0, 0)),
+      },
+    });
+    expect(row.created_at?.getUTCFullYear()).toBe(2098);
+  });
+});