feat: Add Ollama AI integration for automatic mail template generation

✨ New Features:
- 🤖 AI-powered mail template generation with Ollama
- 📧 Test mail sending with preview
- 🔧 Ollama server and model management
- 🎨 Beautiful AI generation dialog in Templates page
- ⚙️ Ollama settings panel with connection test

Backend:
- Add ollama.service.js - Ollama API integration
- Add ollama.controller.js - Template generation endpoint
- Add ollama.routes.js - /api/ollama/* routes
- Support for multiple Ollama models (llama3.2, mistral, gemma)
- JSON-formatted AI responses with subject + HTML body
- Configurable server URL and model selection

Frontend:
- Settings: Ollama configuration panel
  - Server URL input
  - Model selection
  - Connection test with model listing
- Templates: AI generation dialog
  - Company name, scenario, employee info inputs
  - Custom prompt for AI instructions
  - Auto-save to database
  - Test mail sending functionality

Documentation:
- OLLAMA_SETUP.md - Comprehensive setup guide
- Installation instructions
- Model recommendations
- Usage examples
- Troubleshooting

Tech Stack:
- Ollama API integration (REST)
- Axios HTTP client
- React dialogs with MUI
- Self-hosted AI (privacy-friendly)
- Zero external API dependencies

Example Usage:
  Company: Garanti Bankası
  Scenario: Account security warning
  → AI generates professional phishing test mail in seconds!

backend/src/app.js

@@ -87,6 +87,7 @@ app.use('/api/companies', require('./routes/company.routes'));
 app.use('/api/tokens', require('./routes/token.routes'));
 app.use('/api/templates', require('./routes/template.routes'));
 app.use('/api/settings', require('./routes/settings.routes'));
+app.use('/api/ollama', require('./routes/ollama.routes'));
 app.use('/api/stats', require('./routes/stats.routes'));
 
 // Public tracking route (no rate limit on this specific route)