Add Linker and Optimizer modules with API integration and frontend components

- Added Linker and Optimizer apps to `INSTALLED_APPS` in `settings.py`.
- Configured API endpoints for Linker and Optimizer in `urls.py`.
- Implemented `OptimizeContentFunction` for content optimization in the AI module.
- Created prompts for content optimization and site structure generation.
- Updated `OptimizerService` to utilize the new AI function for content optimization.
- Developed frontend components including dashboards and content lists for Linker and Optimizer.
- Integrated new routes and sidebar navigation for Linker and Optimizer in the frontend.
- Enhanced content management with source and sync status filters in the Writer module.
- Comprehensive test coverage added for new features and components.

backend/igny8_core/modules/linker/__init__.py

@@ -0,0 +1,2 @@
+default_app_config = 'igny8_core.modules.linker.apps.LinkerConfig'
+

backend/igny8_core/modules/linker/apps.py

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+from django.apps import AppConfig
+
+
+class LinkerConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'igny8_core.modules.linker'
+    verbose_name = 'Linker Module'
+

backend/igny8_core/modules/linker/serializers.py

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+from rest_framework import serializers
+from igny8_core.business.content.models import Content
+
+
+class LinkContentSerializer(serializers.Serializer):
+    """Serializer for linking content"""
+    content_id = serializers.IntegerField(required=True)
+    
+    def validate_content_id(self, value):
+        try:
+            content = Content.objects.get(id=value)
+            account = self.context['request'].user.account if hasattr(self.context['request'].user, 'account') else None
+            if account and content.account != account:
+                raise serializers.ValidationError("Content not found or access denied")
+            return value
+        except Content.DoesNotExist:
+            raise serializers.ValidationError("Content not found")
+
+
+class BatchLinkContentSerializer(serializers.Serializer):
+    """Serializer for batch linking"""
+    content_ids = serializers.ListField(
+        child=serializers.IntegerField(),
+        min_length=1,
+        max_length=50
+    )
+    
+    def validate_content_ids(self, value):
+        account = self.context['request'].user.account if hasattr(self.context['request'].user, 'account') else None
+        if not account:
+            raise serializers.ValidationError("Account not found")
+        
+        content_ids = Content.objects.filter(
+            id__in=value,
+            account=account
+        ).values_list('id', flat=True)
+        
+        if len(content_ids) != len(value):
+            raise serializers.ValidationError("Some content IDs are invalid or inaccessible")
+        
+        return list(content_ids)
+

backend/igny8_core/modules/linker/tests/__init__.py

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+# Linker module tests
+

backend/igny8_core/modules/linker/tests/test_views.py

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+"""
+Tests for Linker API endpoints
+"""
+from unittest.mock import patch
+from django.test import TestCase
+from rest_framework.test import APIClient
+from rest_framework import status
+from igny8_core.business.content.models import Content
+from igny8_core.business.billing.exceptions import InsufficientCreditsError
+from igny8_core.api.tests.test_integration_base import IntegrationTestBase
+
+
+class LinkerAPITests(IntegrationTestBase):
+    """Tests for Linker API endpoints"""
+    
+    def setUp(self):
+        super().setUp()
+        self.client = APIClient()
+        self.client.force_authenticate(user=self.user)
+        
+        # Create test content
+        self.content = Content.objects.create(
+            account=self.account,
+            site=self.site,
+            sector=self.sector,
+            title="Test Content",
+            html_content="<p>Test content.</p>",
+            word_count=100,
+            status='draft'
+        )
+    
+    def test_process_endpoint_requires_authentication(self):
+        """Test that process endpoint requires authentication"""
+        client = APIClient()  # Not authenticated
+        response = client.post('/api/v1/linker/process/', {
+            'content_id': self.content.id
+        })
+        
+        self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
+    
+    @patch('igny8_core.modules.linker.views.LinkerService.process')
+    def test_process_endpoint_success(self, mock_process):
+        """Test successful processing"""
+        mock_content = Content.objects.create(
+            account=self.account,
+            site=self.site,
+            sector=self.sector,
+            title="Linked Content",
+            html_content="<p>Linked.</p>",
+            internal_links=[{'content_id': 1, 'anchor_text': 'test'}],
+            linker_version=1,
+            word_count=100
+        )
+        mock_process.return_value = mock_content
+        
+        response = self.client.post('/api/v1/linker/process/', {
+            'content_id': self.content.id
+        }, format='json')
+        
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertTrue(response.data['success'])
+        self.assertEqual(response.data['data']['content_id'], self.content.id)
+        self.assertEqual(response.data['data']['links_added'], 1)
+    
+    def test_process_endpoint_invalid_content_id(self):
+        """Test process endpoint with invalid content ID"""
+        response = self.client.post('/api/v1/linker/process/', {
+            'content_id': 99999
+        }, format='json')
+        
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+    
+    @patch('igny8_core.modules.linker.views.LinkerService.process')
+    def test_process_endpoint_insufficient_credits(self, mock_process):
+        """Test process endpoint with insufficient credits"""
+        mock_process.side_effect = InsufficientCreditsError("Insufficient credits")
+        
+        response = self.client.post('/api/v1/linker/process/', {
+            'content_id': self.content.id
+        }, format='json')
+        
+        self.assertEqual(response.status_code, status.HTTP_402_PAYMENT_REQUIRED)
+    
+    @patch('igny8_core.modules.linker.views.LinkerService.batch_process')
+    def test_batch_process_endpoint_success(self, mock_batch):
+        """Test successful batch processing"""
+        content2 = Content.objects.create(
+            account=self.account,
+            site=self.site,
+            sector=self.sector,
+            title="Content 2",
+            word_count=100
+        )
+        
+        mock_batch.return_value = [self.content, content2]
+        
+        response = self.client.post('/api/v1/linker/batch_process/', {
+            'content_ids': [self.content.id, content2.id]
+        }, format='json')
+        
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertTrue(response.data['success'])
+        self.assertEqual(len(response.data['data']), 2)
+    
+    def test_batch_process_endpoint_validation(self):
+        """Test batch process endpoint validation"""
+        response = self.client.post('/api/v1/linker/batch_process/', {
+            'content_ids': []  # Empty list
+        }, format='json')
+        
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+    
+    def test_process_endpoint_respects_account_isolation(self):
+        """Test that process endpoint respects account isolation"""
+        from igny8_core.auth.models import Account
+        other_account = Account.objects.create(
+            name="Other Account",
+            slug="other",
+            plan=self.plan,
+            owner=self.user
+        )
+        
+        other_content = Content.objects.create(
+            account=other_account,
+            site=self.site,
+            sector=self.sector,
+            title="Other Content",
+            word_count=100
+        )
+        
+        response = self.client.post('/api/v1/linker/process/', {
+            'content_id': other_content.id
+        }, format='json')
+        
+        # Should return 400 because content belongs to different account
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+

backend/igny8_core/modules/linker/urls.py

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+from django.urls import include, path
+from rest_framework.routers import DefaultRouter
+
+from igny8_core.modules.linker.views import LinkerViewSet
+
+router = DefaultRouter()
+router.register(r'', LinkerViewSet, basename='linker')
+
+urlpatterns = [
+    path('', include(router.urls)),
+]
+

backend/igny8_core/modules/linker/views.py

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+import logging
+from rest_framework import status
+from rest_framework.decorators import action
+from rest_framework.viewsets import ViewSet
+from drf_spectacular.utils import extend_schema, extend_schema_view
+
+from igny8_core.api.permissions import IsAuthenticatedAndActive, IsEditorOrAbove
+from igny8_core.api.response import success_response, error_response
+from igny8_core.api.throttles import DebugScopedRateThrottle
+from igny8_core.business.content.models import Content
+from igny8_core.business.linking.services.linker_service import LinkerService
+from igny8_core.business.billing.exceptions import InsufficientCreditsError
+from igny8_core.modules.linker.serializers import (
+    LinkContentSerializer,
+    BatchLinkContentSerializer,
+)
+
+logger = logging.getLogger(__name__)
+
+
+@extend_schema_view(
+    process=extend_schema(tags=['Linker']),
+    batch_process=extend_schema(tags=['Linker']),
+)
+class LinkerViewSet(ViewSet):
+    """
+    API endpoints for internal linking operations.
+    Unified API Standard v1.0 compliant
+    """
+    permission_classes = [IsAuthenticatedAndActive, IsEditorOrAbove]
+    throttle_scope = 'linker'
+    throttle_classes = [DebugScopedRateThrottle]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.linker_service = LinkerService()
+
+    @action(detail=False, methods=['post'])
+    def process(self, request):
+        """
+        Process a single content item for internal linking.
+        
+        POST /api/v1/linker/process/
+        {
+            "content_id": 123
+        }
+        """
+        serializer = LinkContentSerializer(data=request.data, context={'request': request})
+        if not serializer.is_valid():
+            return error_response(serializer.errors, status=status.HTTP_400_BAD_REQUEST, request=request)
+        
+        content_id = serializer.validated_data['content_id']
+        
+        try:
+            content = self.linker_service.process(content_id)
+            
+            result = {
+                'content_id': content.id,
+                'links_added': len(content.internal_links) if content.internal_links else 0,
+                'links': content.internal_links or [],
+                'linker_version': content.linker_version,
+                'success': True,
+            }
+            
+            return success_response(result, request=request)
+            
+        except ValueError as e:
+            return error_response({'error': str(e)}, status=status.HTTP_400_BAD_REQUEST, request=request)
+        except InsufficientCreditsError as e:
+            return error_response({'error': str(e)}, status=status.HTTP_402_PAYMENT_REQUIRED, request=request)
+        except Exception as e:
+            logger.error(f"Error processing content {content_id}: {str(e)}", exc_info=True)
+            return error_response({'error': 'Internal server error'}, status=status.HTTP_500_INTERNAL_SERVER_ERROR, request=request)
+
+    @action(detail=False, methods=['post'])
+    def batch_process(self, request):
+        """
+        Process multiple content items for internal linking.
+        
+        POST /api/v1/linker/batch_process/
+        {
+            "content_ids": [123, 456, 789]
+        }
+        """
+        serializer = BatchLinkContentSerializer(data=request.data, context={'request': request})
+        if not serializer.is_valid():
+            return error_response(serializer.errors, status=status.HTTP_400_BAD_REQUEST, request=request)
+        
+        content_ids = serializer.validated_data['content_ids']
+        
+        try:
+            results = self.linker_service.batch_process(content_ids)
+            
+            response_data = []
+            for content in results:
+                response_data.append({
+                    'content_id': content.id,
+                    'links_added': len(content.internal_links) if content.internal_links else 0,
+                    'links': content.internal_links or [],
+                    'linker_version': content.linker_version,
+                    'success': True,
+                })
+            
+            return success_response(response_data, request=request)
+            
+        except Exception as e:
+            logger.error(f"Error batch processing content: {str(e)}", exc_info=True)
+            return error_response({'error': 'Internal server error'}, status=status.HTTP_500_INTERNAL_SERVER_ERROR, request=request)
+