Add admin panel, WebSocket support, and API versioning

Introduce an admin portal (React + Nginx), WebSocket routing, and
API versioning middleware with `/api/v1/` prefix deprecation.
Add master API key authentication, new Prometheus metrics for AI
token consumption and active WebSockets, and extend S3 config
with a public endpoint URL. Update test paths and fixtures to
align with the new routing structure.

sdk/tests/test_client.py

@@ -0,0 +1,54 @@
+import pytest
+import respx
+from httpx import Response
+
+from imago_client import HubClient, ImagoError, APIError, QuotaError, AuthError
+
+@pytest.fixture
+def base_url():
+    return "http://testserver"
+
+@pytest.fixture
+def api_key():
+    return "sk-test-key"
+
+@pytest.mark.asyncio
+async def test_client_initialization(base_url, api_key):
+    client = HubClient(base_url, api_key=api_key)
+    assert client.base_url == "http://testserver"
+    assert client.api_key == "sk-test-key"
+    assert "X-API-Key" in client._http_client.headers
+    await client.close()
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_auth_error(base_url, api_key):
+    respx.get(f"{base_url}/api/v1/images").mock(return_value=Response(401, json={"detail": "Unauthorized"}))
+    
+    async with HubClient(base_url, api_key="wrong") as client:
+        with pytest.raises(AuthError):
+            await client.images.list()
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_quota_error(base_url, api_key):
+    respx.get(f"{base_url}/api/v1/images").mock(return_value=Response(429, json={"detail": "Rate Limit Exceeded"}))
+    
+    async with HubClient(base_url, api_key=api_key) as client:
+        with pytest.raises(QuotaError):
+            await client.images.list()
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_api_error_retry(base_url, api_key):
+    route = respx.get(f"{base_url}/api/v1/images")
+    route.side_effect = [
+        Response(502, json={"error": "Bad Gateway"}),
+        Response(200, json={"items": []})
+    ]
+    
+    async with HubClient(base_url, api_key=api_key) as client:
+        # Should automatically retry on 502
+        response = await client.images.list()
+        assert response == {"items": []}
+        assert route.call_count == 2

sdk/tests/test_images.py

@@ -0,0 +1,76 @@
+import pytest
+import respx
+from httpx import Response
+
+from imago_client import HubClient, HubImage
+
+@pytest.fixture
+def base_url():
+    return "http://testserver"
+
+@pytest.fixture
+def api_key():
+    return "sk-test-key"
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_get_image(base_url, api_key):
+    mock_data = {
+        "id": 1,
+        "uuid": "fake-uuid",
+        "original_name": "test.jpg",
+        "processing_status": "done"
+    }
+    respx.get(f"{base_url}/api/v1/images/1").mock(return_value=Response(200, json=mock_data))
+    
+    async with HubClient(base_url, api_key=api_key) as client:
+        img = await client.images.get(1)
+        
+        assert isinstance(img, HubImage)
+        assert img.id == 1
+        assert img.uuid == "fake-uuid"
+        assert img.processing_status == "done"
+        assert img.original_name == "test.jpg"
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_upload_image(base_url, api_key):
+    mock_data = {
+        "id": 2,
+        "uuid": "new-uuid",
+        "original_name": "upload.jpg",
+        "processing_status": "pending"
+    }
+    respx.post(f"{base_url}/api/v1/images/upload").mock(return_value=Response(200, json=mock_data))
+    
+    async with HubClient(base_url, api_key=api_key) as client:
+        img = await client.images.upload(b"fakebytes", "upload.jpg", "image/jpeg")
+        
+        assert isinstance(img, HubImage)
+        assert img.id == 2
+        assert img.processing_status == "pending"
+
+@pytest.mark.asyncio
+@respx.mock
+async def test_list_images(base_url, api_key):
+    mock_response = {
+        "total": 1,
+        "page": 1,
+        "size": 50,
+        "items": [
+            {
+                "id": 1,
+                "uuid": "fake-uuid",
+                "original_name": "test.jpg",
+                "processing_status": "done"
+            }
+        ]
+    }
+    respx.get(f"{base_url}/api/v1/images?page=1&size=50").mock(return_value=Response(200, json=mock_response))
+    
+    async with HubClient(base_url, api_key=api_key) as client:
+        result = await client.images.list()
+        
+        assert result["total"] == 1
+        assert len(result["items"]) == 1
+        assert result["items"][0]["id"] == 1