django admin Groups reorg, Frontend udpates for site settings, #Migration runs

docs/plans/4th-jan-refactor/django-plan.md

@@ -202,9 +202,53 @@ Django Admin
 
 ---
 
-## Next Steps (From Original Plan)
+## Phase 2: AI Models & Credits Refactor - COMPLETED
+
+### IntegrationProvider Model Created
+- New model: `IntegrationProvider` in `modules/system/models.py`
+- Centralized storage for ALL external service API keys
+- Supports: AI providers, payment gateways, email services, storage
+- Migrated OpenAI and Runware API keys from GlobalIntegrationSettings
+- Admin interface added in `modules/system/admin.py`
+- Added to admin sidebar under "Global Settings"
+
+### AIModelConfig Enhanced
+- Added `tokens_per_credit` - for text models (e.g., 1000 tokens = 1 credit)
+- Added `credits_per_image` - for image models (e.g., 1, 5, 15 credits)
+- Added `quality_tier` - for frontend UI (basic/quality/premium)
+- Migration `0025_add_aimodel_credit_fields` adds fields
+- Migration `0026_populate_aimodel_credits` sets initial values
+
+### ModelRegistry Updated
+- Removed fallback to `constants.py` - database is now authoritative
+- Added `get_provider()`, `get_api_key()`, `get_api_secret()`, `get_webhook_secret()`
+- Provider caching with TTL
+
+### CreditService Updated
+- Added `calculate_credits_for_image(model_name, num_images)` - uses AIModelConfig.credits_per_image
+- Added `calculate_credits_from_tokens_by_model(model_name, total_tokens)` - uses AIModelConfig.tokens_per_credit
+- Added `deduct_credits_for_image()` - convenience method
+
+### Files Changed (Phase 2)
+| File | Change |
+|------|--------|
+| `modules/system/models.py` | Added IntegrationProvider model |
+| `modules/system/admin.py` | Added IntegrationProviderAdmin |
+| `business/billing/models.py` | Added tokens_per_credit, credits_per_image, quality_tier to AIModelConfig |
+| `business/billing/services/credit_service.py` | Added image/model-based credit calculation |
+| `ai/model_registry.py` | Removed constants fallback, added provider methods |
+| `ai/ai_core.py` | Use ModelRegistry for API keys, removed constants fallback |
+| `ai/constants.py` | Marked MODEL_RATES, IMAGE_MODEL_RATES as DEPRECATED |
+| `ai/settings.py` | Use ModelRegistry for model validation |
+| `ai/validators.py` | Removed constants fallback |
+| `modules/system/integration_views.py` | Use ModelRegistry for cost calculation |
+| `modules/billing/serializers.py` | Added new fields to AIModelConfigSerializer |
+
+---
+
+## Next Steps
 
 1. ✅ **Django Admin Cleanup** - DONE
 2. ⏳ **Simplify AI Settings** - Merge content + image settings into AccountSettings
-3. ⏳ **Create IntegrationProvider** - Move API keys to dedicated model
-4. ⏳ **AIModelConfig Enhancement** - Add tokens_per_credit, credits_per_image, quality_tier
+3. ✅ **Create IntegrationProvider** - DONE (API keys now in dedicated model)
+4. ✅ **AIModelConfig Enhancement** - DONE (tokens_per_credit, credits_per_image, quality_tier added)