feat: production deployment - full update with providers, admin, glossaries, pricing, tests

Major changes across backend, frontend, infrastructure:
- Provider system with model selection (Google, DeepL, OpenAI, Ollama, Google Cloud)
- Admin panel: user management, pricing, settings
- Glossary system with CSV import/export
- Subscription and tier quota management
- Security hardening (rate limiting, API key auth, path traversal fixes)
- Docker compose for dev, prod, and IONOS deployment
- Alembic migrations for new tables
- Frontend: dashboard, pricing page, landing page, i18n (en/fr)
- Test suite and verification scripts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/test_providers/test_google_provider.py

@@ -0,0 +1,180 @@
+"""
+Tests for the GoogleTranslationProvider.
+"""
+
+import pytest
+from unittest.mock import patch, MagicMock
+
+from services.providers.google_provider import (
+    GoogleTranslationProvider,
+    get_google_provider,
+)
+from services.providers.schemas import TranslationRequest, TranslationResponse
+
+
+class TestGoogleTranslationProvider:
+    """Tests for GoogleTranslationProvider."""
+
+    @pytest.fixture
+    def provider(self):
+        """Create a Google provider instance."""
+        return GoogleTranslationProvider(use_cache=False)
+
+    @pytest.fixture
+    def provider_with_cache(self):
+        """Create a Google provider with caching enabled."""
+        return GoogleTranslationProvider(use_cache=True)
+
+    def test_get_name(self, provider):
+        """Test provider name."""
+        assert provider.get_name() == "google"
+
+    def test_is_available(self, provider):
+        """Test availability check."""
+        result = provider.is_available()
+        assert isinstance(result, bool)
+
+    def test_translate_text_empty(self, provider):
+        """Test translating empty text."""
+        request = TranslationRequest(text="", target_language="fr")
+        response = provider.translate_text(request)
+
+        assert response.translated_text == ""
+        assert response.provider_name == "google"
+        assert response.from_cache is False
+
+    def test_translate_text_whitespace(self, provider):
+        """Test translating whitespace-only text."""
+        request = TranslationRequest(text="   ", target_language="fr")
+        response = provider.translate_text(request)
+
+        assert response.translated_text == "   "
+
+    @patch(
+        "services.providers.google_provider.GoogleTranslationProvider._get_translator"
+    )
+    def test_translate_text_success(self, mock_get_translator, provider):
+        """Test successful translation."""
+        mock_translator = MagicMock()
+        mock_translator.translate.return_value = "Bonjour"
+        mock_get_translator.return_value = mock_translator
+
+        request = TranslationRequest(text="Hello", target_language="fr")
+        response = provider.translate_text(request)
+
+        assert response.translated_text == "Bonjour"
+        assert response.provider_name == "google"
+        assert response.from_cache is False
+
+    @patch(
+        "services.providers.google_provider.GoogleTranslationProvider._get_translator"
+    )
+    def test_translate_text_with_source_language(self, mock_get_translator, provider):
+        """Test translation with explicit source language."""
+        mock_translator = MagicMock()
+        mock_translator.translate.return_value = "Bonjour"
+        mock_get_translator.return_value = mock_translator
+
+        request = TranslationRequest(
+            text="Hello", target_language="fr", source_language="en"
+        )
+        response = provider.translate_text(request)
+
+        mock_get_translator.assert_called_once_with("en", "fr")
+        assert response.translated_text == "Bonjour"
+
+    @patch(
+        "services.providers.google_provider.GoogleTranslationProvider._get_translator"
+    )
+    def test_translate_text_error_fallback(self, mock_get_translator, provider):
+        """Test that translation errors return original text and structured error (Story 2.2)."""
+        mock_get_translator.side_effect = Exception("API Error")
+
+        request = TranslationRequest(text="Hello", target_language="fr")
+        response = provider.translate_text(request)
+
+        assert response.translated_text == "Hello"
+        assert response.provider_name == "google"
+        assert response.error is not None
+        assert response.error_code is not None
+
+    def test_translate_batch_empty(self, provider):
+        """Test batch translation with empty list."""
+        responses = provider.translate_batch([])
+        assert responses == []
+
+    @patch.object(GoogleTranslationProvider, "translate_text")
+    def test_translate_batch(self, mock_translate, provider):
+        """Test batch translation."""
+        mock_translate.side_effect = [
+            TranslationResponse(translated_text="Bonjour", provider_name="google"),
+            TranslationResponse(translated_text="Monde", provider_name="google"),
+        ]
+
+        requests = [
+            TranslationRequest(text="Hello", target_language="fr"),
+            TranslationRequest(text="World", target_language="fr"),
+        ]
+        responses = provider.translate_batch(requests)
+
+        assert len(responses) == 2
+        assert responses[0].translated_text == "Bonjour"
+        assert responses[1].translated_text == "Monde"
+
+    def test_health_check(self, provider):
+        """Test health check."""
+        status = provider.health_check()
+
+        assert status.name == "google"
+        assert isinstance(status.available, bool)
+        assert status.latency_ms is not None
+
+    def test_get_google_provider_singleton(self):
+        """Test that get_google_provider returns same instance."""
+        provider1 = get_google_provider()
+        provider2 = get_google_provider()
+
+        assert provider1 is provider2
+
+
+class TestGoogleProviderCaching:
+    """Tests for Google provider caching functionality."""
+
+    @pytest.fixture
+    def mock_cache(self):
+        """Create a mock cache."""
+        cache = MagicMock()
+        cache.get.return_value = None
+        return cache
+
+    def test_cache_hit(self, mock_cache):
+        """Test that cache hits return cached result."""
+        mock_cache.get.return_value = "Cached Translation"
+
+        provider = GoogleTranslationProvider(use_cache=True)
+        provider._cache = mock_cache
+
+        request = TranslationRequest(text="Hello", target_language="fr")
+        response = provider.translate_text(request)
+
+        assert response.translated_text == "Cached Translation"
+        assert response.from_cache is True
+
+    @patch(
+        "services.providers.google_provider.GoogleTranslationProvider._get_translator"
+    )
+    def test_cache_set_on_miss(self, mock_get_translator, mock_cache):
+        """Test that translations are cached on miss."""
+        mock_translator = MagicMock()
+        mock_translator.translate.return_value = "Bonjour"
+        mock_get_translator.return_value = mock_translator
+
+        provider = GoogleTranslationProvider(use_cache=True)
+        provider._cache = mock_cache
+
+        request = TranslationRequest(text="Hello", target_language="fr")
+        provider.translate_text(request)
+
+        mock_cache.set.assert_called_once_with(
+            "Hello", "fr", "auto", "google", "Bonjour"
+        )