refactor: support remote Ollama server in docker-compose

- Remove Ollama service from docker-compose.yml (now external/remote)
- Remove ollama_data volume and network configuration
- Simplify compose to only llm-monitor service
- Use env_file for all configuration from .env
- Make API_PORT dynamic with ${API_PORT:-8000}
- Update env.example with Ollama remote server examples:
  - Local development: http://localhost:11434
  - Remote server: http://ollama.example.com:11434
  - Remote with SSL: https://ollama.example.com
- Improve documentation for remote Ollama setup

This allows deployment against any Ollama server (local or remote).

docker-compose.yml

@@ -1,23 +1,6 @@
 version: '3.8'
 
 services:
-  # Ollama Service
-  ollama:
-    image: ollama/ollama:latest
-    container_name: ollama-server
-    ports:
-      - "11434:11434"
-    environment:
-      OLLAMA_HOST: 0.0.0.0:11434
-    volumes:
-      - ollama_data:/root/.ollama
-    restart: unless-stopped
-    # Keep container running until stopped
-    stdin_open: true
-    tty: true
-    networks:
-      - llm-monitor-network
-
   # LLM Monitor Dashboard
   llm-monitor:
     build:
@@ -25,45 +8,22 @@ services:
       dockerfile: Dockerfile
     container_name: llm-monitor-app
     ports:
-      - "8000:8000"
-    environment:
-      # Carica variabili da .env
-      OLLAMA_HOST: http://ollama:11434
-      OLLAMA_TIMEOUT: 30
-      API_HOST: 0.0.0.0
-      API_PORT: 8000
-      API_WORKERS: 4
-      CORS_ORIGINS: http://localhost:3000,http://localhost:5173,http://localhost:8000
-      LOG_LEVEL: INFO
-      ENVIRONMENT: production
+      - "${API_PORT:-8000}:${API_PORT:-8000}"
     env_file:
       - .env
-    depends_on:
-      - ollama
     restart: unless-stopped
     stdin_open: true
     tty: true
-    networks:
-      - llm-monitor-network
     # Health check
     healthcheck:
-      test: ["CMD", "curl", "-f", "http://localhost:8000/api/v1/health"]
+      test: ["CMD", "curl", "-f", "http://localhost:${API_PORT:-8000}/api/v1/health"]
       interval: 30s
       timeout: 10s
       retries: 3
       start_period: 10s
 
-volumes:
-  ollama_data:
-    driver: local
-
-networks:
-  llm-monitor-network:
-    driver: bridge
-
 # Istruzioni di avvio:
 # docker compose up -d          # Avvia i servizi
 # docker compose logs -f        # Visualizza i log
 # docker compose down           # Ferma i servizi
-# docker compose stop ollama    # Ferma solo Ollama
-# docker compose start ollama   # Riavvia Ollama
+# docker compose restart        # Riavvia i servizi