fix: Ollama should only show as configured when URL is explicitly set

Previously Ollama always showed as 'Available' even if not set up.
Now it only shows as configured when user has entered an OllamaBaseURL.

internal/config/ai.go

@@ -149,8 +149,8 @@ func (c *AIConfig) HasProvider(provider string) bool {
 	case AIProviderDeepSeek:
 		return c.DeepSeekAPIKey != ""
 	case AIProviderOllama:
-		// Ollama is available if URL is set (or default localhost)
-		return true // Always available for attempt
+		// Ollama is only "configured" if user has explicitly set a base URL
+		return c.OllamaBaseURL != ""
 	default:
 		return false
 	}