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.

tests/test_ocr_extended.py

@@ -8,11 +8,17 @@ def test_detect_language():
     assert _detect_language("") == "unknown"
     assert _detect_language("123456789") == "unknown"
 
+@pytest.mark.asyncio
 @patch("app.services.ocr_service.pytesseract")
 @patch("app.services.ocr_service.PILImage")
 @patch("app.services.ocr_service.Path.exists", return_value=True)
 @patch("app.services.ocr_service.settings")
-def test_extract_text_success(mock_settings, mock_path_exists, mock_pil, mock_tesseract):
+@patch("app.services.ocr_service.get_storage_backend")
+async def test_extract_text_success(mock_get_storage_backend, mock_settings, mock_path_exists, mock_pil, mock_tesseract):
+    from unittest.mock import AsyncMock
+    mock_backend = MagicMock()
+    mock_backend.get_bytes = AsyncMock(return_value=b"fake")
+    mock_get_storage_backend.return_value = mock_backend
     mock_settings.OCR_ENABLED = True
     mock_settings.OCR_LANGUAGES = "fra+eng"
     mock_settings.TESSERACT_CMD = None
@@ -26,16 +32,17 @@ def test_extract_text_success(mock_settings, mock_path_exists, mock_pil, mock_te
     # Mock image_to_string
     mock_tesseract.image_to_string.return_value = "This is a test OCR output."
     
-    result = extract_text("fake/path.jpg")
+    result = await extract_text("fake/path.jpg")
     
     assert result["has_text"] is True
     assert result["text"] == "This is a test OCR output."
     assert result["confidence"] == 0.8  # (90+80+70)/3 / 100 = 0.8
     assert result["language"] == "en"
 
+@pytest.mark.asyncio
 @patch("app.services.ocr_service.settings")
-def test_extract_text_disabled(mock_settings):
+async def test_extract_text_disabled(mock_settings):
     mock_settings.OCR_ENABLED = False
-    result = extract_text("any/path.jpg")
+    result = await extract_text("any/path.jpg")
     assert result["has_text"] is False
     assert result["text"] is None