Add SEO fields to Tasks model, improve content generation response handling, and enhance progress bar animation

- Added primary_keyword, secondary_keywords, tags, and categories fields to Tasks model
- Updated generate_content function to handle full JSON response with all SEO fields
- Improved progress bar animation: smooth 1% increments every 300ms
- Enhanced step detection for content generation vs clustering vs ideas
- Fixed progress modal to show correct messages for each function type
- Added comprehensive logging to Keywords and Tasks pages for AI functions
- Fixed error handling to show meaningful error messages instead of generic failures

backend/igny8_core/ai/constants.py

@@ -0,0 +1,41 @@
+"""
+AI Constants - Model pricing, valid models, and configuration constants
+"""
+# Model pricing (per 1M tokens) - EXACT from reference plugin model-rates-config.php
+MODEL_RATES = {
+    'gpt-4.1': {'input': 2.00, 'output': 8.00},
+    'gpt-4o-mini': {'input': 0.15, 'output': 0.60},
+    'gpt-4o': {'input': 2.50, 'output': 10.00},
+}
+
+# Image model pricing (per image) - EXACT from reference plugin
+IMAGE_MODEL_RATES = {
+    'dall-e-3': 0.040,
+    'dall-e-2': 0.020,
+    'gpt-image-1': 0.042,
+    'gpt-image-1-mini': 0.011,
+}
+
+# Valid OpenAI image generation models (only these work with /v1/images/generations endpoint)
+VALID_OPENAI_IMAGE_MODELS = {
+    'dall-e-3',
+    'dall-e-2',
+    # Note: gpt-image-1 and gpt-image-1-mini are NOT valid for OpenAI's /v1/images/generations endpoint
+}
+
+# Valid image sizes per model (from OpenAI official documentation)
+VALID_SIZES_BY_MODEL = {
+    'dall-e-3': ['1024x1024', '1024x1792', '1792x1024'],
+    'dall-e-2': ['256x256', '512x512', '1024x1024'],
+}
+
+# Default model
+DEFAULT_AI_MODEL = 'gpt-4.1'
+
+# JSON mode supported models
+JSON_MODE_MODELS = ['gpt-4o', 'gpt-4o-mini', 'gpt-4-turbo-preview']
+
+# Debug mode - controls console logging
+# Set to False in production to disable verbose logging
+DEBUG_MODE = True
+