fix(orders): release PO number against creation year; tighten sort-dir + enum typing

Addresses review of the issued-orders service: deleteIssuedOrder now derives the release year from created_at (cross-year deletes reclaim the right sequence); list sort direction is normalized to asc/desc; status cast uses $Enums instead of as-never. Adds a cross-year delete test.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/__tests__/issued-orders.test.ts

@@ -195,4 +195,25 @@ describe("deleteIssuedOrder", () => {
     ).toBe(0);
     expect((await previewIssuedOrderNumber()).number).toBe(before);
   });
+
+  it("releases the number against the order's creation year, not the current year", async () => {
+    const priorYear = new Date().getFullYear() - 1;
+    // Allocate a real prior-year number (consumes that year's sequence: 0 -> 1)
+    // so the PO number matches the prior year's current highest.
+    const { number: poNumber } = await generateIssuedOrderNumber(priorYear);
+    const order = await createIssuedOrder({ po_number: poNumber });
+    createdIds.push(order.id);
+    // Backdate creation into the prior year so delete derives that year.
+    await prisma.issued_orders.update({
+      where: { id: order.id },
+      data: { created_at: new Date(priorYear, 5, 1, 12, 0, 0) },
+    });
+    await deleteIssuedOrder(order.id);
+    // The prior-year sequence must be decremented (1 -> 0). With the old
+    // current-year bug it would stay at 1 (no current-year row to match).
+    const seq = await prisma.number_sequences.findFirst({
+      where: { type: "issued_order", year: priorYear },
+    });
+    expect(seq?.last_number).toBe(0);
+  });
 });