feat(backend): sync endpoints + all models + seed + order workflow

- All business models: Vehicle, Order, OrderLine, Invoice, Appointment,
  CatalogMarca/Model/Ansamblu/Norma/Pret/TipDeviz/TipMotor, Mecanic
- Sync endpoints: GET /sync/full, GET /sync/changes?since=, POST /sync/push
  with tenant isolation and last-write-wins conflict resolution
- Order CRUD with state machine: DRAFT -> VALIDAT -> FACTURAT
  Auto-recalculates totals (manopera + materiale)
- Vehicle CRUD: list, create, get, update
- Seed data: 24 marci, 11 ansamble, 6 tipuri deviz, 5 tipuri motoare, 3 preturi
- Alembic migration for all business models
- 13 passing tests (auth + sync + orders)

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

backend/tests/test_orders.py

@@ -0,0 +1,145 @@
+import uuid
+from datetime import UTC, datetime
+
+import pytest
+from httpx import ASGITransport, AsyncClient
+
+from app.main import app
+
+
+async def _create_vehicle(client, auth_headers):
+    """Helper to create a vehicle via sync push and return its id."""
+    me = await client.get("/api/auth/me", headers=auth_headers)
+    tenant_id = me.json()["tenant_id"]
+    vid = str(uuid.uuid4())
+    now = datetime.now(UTC).isoformat()
+    await client.post(
+        "/api/sync/push",
+        headers=auth_headers,
+        json={
+            "operations": [
+                {
+                    "table": "vehicles",
+                    "id": vid,
+                    "operation": "INSERT",
+                    "data": {
+                        "id": vid,
+                        "tenant_id": tenant_id,
+                        "nr_inmatriculare": "CT01TST",
+                        "client_nume": "Test Client",
+                        "created_at": now,
+                        "updated_at": now,
+                    },
+                    "timestamp": now,
+                }
+            ]
+        },
+    )
+    return vid
+
+
+@pytest.mark.asyncio
+async def test_order_workflow(client, auth_headers):
+    vid = await _create_vehicle(client, auth_headers)
+
+    # Create order (DRAFT)
+    r = await client.post(
+        "/api/orders",
+        headers=auth_headers,
+        json={"vehicle_id": vid},
+    )
+    assert r.status_code == 200
+    order_id = r.json()["id"]
+
+    # Add manopera line: 2h x 150 = 300
+    r = await client.post(
+        f"/api/orders/{order_id}/lines",
+        headers=auth_headers,
+        json={
+            "tip": "manopera",
+            "descriere": "Reparatie motor",
+            "ore": 2,
+            "pret_ora": 150,
+        },
+    )
+    assert r.status_code == 200
+
+    # Add material line: 2 buc x 50 = 100
+    r = await client.post(
+        f"/api/orders/{order_id}/lines",
+        headers=auth_headers,
+        json={
+            "tip": "material",
+            "descriere": "Filtru ulei",
+            "cantitate": 2,
+            "pret_unitar": 50,
+            "um": "buc",
+        },
+    )
+    assert r.status_code == 200
+
+    # Validate order
+    r = await client.post(
+        f"/api/orders/{order_id}/validate",
+        headers=auth_headers,
+    )
+    assert r.status_code == 200
+    assert r.json()["status"] == "VALIDAT"
+
+    # Get order details
+    r = await client.get(
+        f"/api/orders/{order_id}",
+        headers=auth_headers,
+    )
+    assert r.status_code == 200
+    data = r.json()
+    assert data["total_manopera"] == 300
+    assert data["total_materiale"] == 100
+    assert data["total_general"] == 400
+    assert data["status"] == "VALIDAT"
+    assert len(data["lines"]) == 2
+
+
+@pytest.mark.asyncio
+async def test_cannot_add_line_to_validated_order(client, auth_headers):
+    vid = await _create_vehicle(client, auth_headers)
+
+    # Create and validate order
+    r = await client.post(
+        "/api/orders",
+        headers=auth_headers,
+        json={"vehicle_id": vid},
+    )
+    order_id = r.json()["id"]
+    await client.post(
+        f"/api/orders/{order_id}/validate",
+        headers=auth_headers,
+    )
+
+    # Try to add line to validated order
+    r = await client.post(
+        f"/api/orders/{order_id}/lines",
+        headers=auth_headers,
+        json={
+            "tip": "manopera",
+            "descriere": "Should fail",
+            "ore": 1,
+            "pret_ora": 100,
+        },
+    )
+    assert r.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_list_orders(client, auth_headers):
+    vid = await _create_vehicle(client, auth_headers)
+
+    await client.post(
+        "/api/orders",
+        headers=auth_headers,
+        json={"vehicle_id": vid},
+    )
+
+    r = await client.get("/api/orders", headers=auth_headers)
+    assert r.status_code == 200
+    assert len(r.json()) == 1