feat(orders-ui): add manual order create modal (header only, optional project)

Mirrors the Projects.tsx pattern: useQuery-driven customers + next-number
fetches (enabled only when modal is open), OrderCreatePayload type normalises
customer_id "" → null so the server's CreateOrderSchema never receives 0.

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

src/admin/pages/Orders.tsx

@@ -1,16 +1,23 @@
 import { useState } from "react";
+import { useQuery } from "@tanstack/react-query";
 import { useAlert } from "../context/AlertContext";
 import { useAuth } from "../context/AuthContext";
 import { Link } from "react-router-dom";
 import Forbidden from "../components/Forbidden";
 import { motion } from "framer-motion";
 import ConfirmModal from "../components/ConfirmModal";
+import FormModal from "../components/FormModal";
+import FormField from "../components/FormField";
 
 import { formatCurrency, formatDate, czechPlural } from "../utils/formatters";
 import SortIcon from "../components/SortIcon";
 import useTableSort from "../hooks/useTableSort";
 import { usePaginatedQuery } from "../hooks/usePaginatedQuery";
-import { orderListOptions } from "../lib/queries/orders";
+import {
+  orderListOptions,
+  orderNextNumberOptions,
+} from "../lib/queries/orders";
+import { offerCustomersOptions } from "../lib/queries/offers";
 import { useApiMutation } from "../lib/queries/mutations";
 import Pagination from "../components/Pagination";
 
@@ -71,6 +78,77 @@ export default function Orders() {
     },
   });
 
+  const [showCreate, setShowCreate] = useState(false);
+  const [createForm, setCreateForm] = useState({
+    customer_id: "",
+    customer_order_number: "",
+    currency: "CZK",
+    vat_rate: "21",
+    apply_vat: true,
+    scope_title: "",
+    scope_description: "",
+    notes: "",
+    create_project: true,
+  });
+  const [creating, setCreating] = useState(false);
+
+  const customersQuery = useQuery({
+    ...offerCustomersOptions(),
+    enabled: showCreate,
+  });
+  const nextNumberQuery = useQuery({
+    ...orderNextNumberOptions(),
+    enabled: showCreate,
+  });
+
+  // The payload normalises customer_id: "" → null. CreateOrderSchema's
+  // customer_id coercion does NOT special-case "", so a raw "" would become
+  // Number("") = 0 and hit a foreign-key violation.
+  type OrderCreatePayload = Omit<typeof createForm, "customer_id"> & {
+    customer_id: number | null;
+  };
+
+  const createMutation = useApiMutation<OrderCreatePayload, { id: number }>({
+    url: () => `${API_BASE}/orders`,
+    method: () => "POST",
+    invalidate: ["orders", "projects", "offers", "invoices"],
+    onSuccess: () => {
+      setShowCreate(false);
+      alert.success("Objednávka byla vytvořena");
+    },
+  });
+
+  const openCreate = () => {
+    setCreateForm({
+      customer_id: "",
+      customer_order_number: "",
+      currency: "CZK",
+      vat_rate: "21",
+      apply_vat: true,
+      scope_title: "",
+      scope_description: "",
+      notes: "",
+      create_project: true,
+    });
+    setShowCreate(true);
+  };
+
+  const handleCreate = async () => {
+    setCreating(true);
+    try {
+      await createMutation.mutateAsync({
+        ...createForm,
+        customer_id: createForm.customer_id
+          ? Number(createForm.customer_id)
+          : null,
+      });
+    } catch (e) {
+      alert.error(e instanceof Error ? e.message : "Chyba připojení");
+    } finally {
+      setCreating(false);
+    }
+  };
+
   const {
     items: orders,
     pagination,
@@ -120,6 +198,27 @@ export default function Orders() {
             )}
           </p>
         </div>
+        {hasPermission("orders.create") && (
+          <div className="admin-page-actions">
+            <button
+              onClick={openCreate}
+              className="admin-btn admin-btn-primary"
+            >
+              <svg
+                width="20"
+                height="20"
+                viewBox="0 0 24 24"
+                fill="none"
+                stroke="currentColor"
+                strokeWidth="2"
+              >
+                <line x1="12" y1="5" x2="12" y2="19" />
+                <line x1="5" y1="12" x2="19" y2="12" />
+              </svg>
+              Vytvořit objednávku
+            </button>
+          </div>
+        )}
       </motion.div>
 
       <motion.div
@@ -377,6 +476,149 @@ export default function Orders() {
         type="danger"
         loading={deleteMutation.isPending}
       />
+
+      <FormModal
+        isOpen={showCreate}
+        onClose={() => setShowCreate(false)}
+        onSubmit={handleCreate}
+        title="Vytvořit objednávku bez nabídky"
+        submitLabel="Vytvořit"
+        loading={creating}
+      >
+        <div className="admin-form">
+          <div className="admin-form-row">
+            <FormField label="Zákazník">
+              <select
+                value={createForm.customer_id}
+                onChange={(e) =>
+                  setCreateForm({ ...createForm, customer_id: e.target.value })
+                }
+                className="admin-form-input"
+              >
+                <option value="">— bez zákazníka —</option>
+                {(customersQuery.data ?? []).map((c) => (
+                  <option key={c.id} value={c.id}>
+                    {c.name}
+                  </option>
+                ))}
+              </select>
+            </FormField>
+            <FormField label="Číslo objednávky zákazníka">
+              <input
+                type="text"
+                value={createForm.customer_order_number}
+                onChange={(e) =>
+                  setCreateForm({
+                    ...createForm,
+                    customer_order_number: e.target.value,
+                  })
+                }
+                className="admin-form-input"
+              />
+            </FormField>
+          </div>
+
+          <div className="admin-form-row">
+            <FormField label="Měna">
+              <select
+                value={createForm.currency}
+                onChange={(e) =>
+                  setCreateForm({ ...createForm, currency: e.target.value })
+                }
+                className="admin-form-input"
+              >
+                <option value="CZK">CZK</option>
+                <option value="EUR">EUR</option>
+                <option value="USD">USD</option>
+                <option value="GBP">GBP</option>
+              </select>
+            </FormField>
+            <FormField label="Sazba DPH (%)">
+              <input
+                type="number"
+                inputMode="numeric"
+                value={createForm.vat_rate}
+                onChange={(e) =>
+                  setCreateForm({ ...createForm, vat_rate: e.target.value })
+                }
+                className="admin-form-input"
+                min="0"
+              />
+            </FormField>
+          </div>
+
+          <FormField label="Předmět (scope)">
+            <input
+              type="text"
+              value={createForm.scope_title}
+              onChange={(e) =>
+                setCreateForm({ ...createForm, scope_title: e.target.value })
+              }
+              className="admin-form-input"
+            />
+          </FormField>
+
+          <FormField label="Popis">
+            <textarea
+              value={createForm.scope_description}
+              onChange={(e) =>
+                setCreateForm({
+                  ...createForm,
+                  scope_description: e.target.value,
+                })
+              }
+              className="admin-form-input"
+              rows={3}
+            />
+          </FormField>
+
+          <FormField label="Poznámka">
+            <textarea
+              value={createForm.notes}
+              onChange={(e) =>
+                setCreateForm({ ...createForm, notes: e.target.value })
+              }
+              className="admin-form-input"
+              rows={2}
+            />
+          </FormField>
+
+          <label className="admin-form-checkbox">
+            <input
+              type="checkbox"
+              checked={createForm.apply_vat}
+              onChange={(e) =>
+                setCreateForm({ ...createForm, apply_vat: e.target.checked })
+              }
+            />
+            <span>Účtovat DPH</span>
+          </label>
+
+          <label className="admin-form-checkbox">
+            <input
+              type="checkbox"
+              checked={createForm.create_project}
+              onChange={(e) =>
+                setCreateForm({
+                  ...createForm,
+                  create_project: e.target.checked,
+                })
+              }
+            />
+            <span>Vytvořit propojený projekt</span>
+          </label>
+
+          <p className="admin-form-hint">
+            Číslo objednávky:{" "}
+            <strong>
+              {nextNumberQuery.data?.number ??
+                nextNumberQuery.data?.next_number ??
+                "…"}
+            </strong>{" "}
+            (přiděleno automaticky)
+          </p>
+        </div>
+      </FormModal>
     </div>
   );
 }