feat(orders): manual order optionally creates a linked project

Add `create_project` flag (default true) to `CreateOrderSchema` and
`CreateOrderData`. When true and `quotation_id` is absent, `createOrder`
creates a `projects` row sharing the order's shared-pool number and
`order_id` link — mirroring the from-quotation flow. The route audits
the new project creation when it occurs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/__tests__/manual-create.test.ts

@@ -1,6 +1,7 @@
 import { describe, it, expect, afterEach } from "vitest";
 import prisma from "../config/database";
 import { createProject } from "../services/projects.service";
+import { createOrder } from "../services/orders.service";
 
 const createdProjectIds: number[] = [];
 const createdOrderIds: number[] = [];
@@ -15,6 +16,62 @@ afterEach(async () => {
   await prisma.number_sequences.deleteMany({ where: { type: "shared" } });
 });
 
+const baseOrder = {
+  status: "prijata" as const,
+  currency: "CZK",
+  language: "cs",
+  vat_rate: 21,
+  apply_vat: true,
+  exchange_rate: 1,
+};
+
+describe("createOrder (manual, optional linked project)", () => {
+  it("creates an order AND a project sharing one number when create_project=true", async () => {
+    const res = await createOrder({
+      ...baseOrder,
+      scope_title: "Ruční zakázka",
+      create_project: true,
+    });
+    expect("id" in res).toBe(true);
+    if (!("id" in res)) return;
+    createdOrderIds.push(res.id);
+    expect(res.project_id).toBeTruthy();
+    const project = await prisma.projects.findUnique({
+      where: { id: res.project_id! },
+    });
+    if (project) createdProjectIds.push(project.id);
+    expect(project?.project_number).toBe(res.order_number);
+    expect(project?.order_id).toBe(res.id);
+  });
+
+  it("creates only the order when create_project=false", async () => {
+    const res = await createOrder({ ...baseOrder, create_project: false });
+    expect("id" in res).toBe(true);
+    if (!("id" in res)) return;
+    createdOrderIds.push(res.id);
+    expect(res.project_id).toBeUndefined();
+  });
+});
+
+describe("shared pool coherence (tracking)", () => {
+  it("order → standalone project → order produce three distinct shared numbers", async () => {
+    const o1 = await createOrder({ ...baseOrder, create_project: true });
+    if ("id" in o1) {
+      createdOrderIds.push(o1.id);
+      if (o1.project_id) createdProjectIds.push(o1.project_id);
+    }
+    const p = await createProject({ name: "Mezi-projekt", status: "aktivni" });
+    if ("project_number" in p) createdProjectIds.push(p.id);
+    const o2 = await createOrder({ ...baseOrder, create_project: false });
+    if ("id" in o2) createdOrderIds.push(o2.id);
+
+    const n1 = "id" in o1 ? o1.order_number : null;
+    const np = "project_number" in p ? p.project_number : null;
+    const n2 = "id" in o2 ? o2.order_number : null;
+    expect(new Set([n1, np, n2]).size).toBe(3);
+  });
+});
+
 describe("createProject (manual, standalone)", () => {
   it("assigns a shared number and is not linked to an order", async () => {
     const result = await createProject({