fix: Add HTTP protocol scheme to service URLs

[doppleware]

This PR addresses high error rates (STATUS_CODE_ERROR) affecting frontend services by adding the HTTP protocol scheme to internal service URLs in the Helm chart configuration.

Changes made:

• Added http:// prefix to all internal service URLs in values.yaml
• Standardized URL format across all service configurations
• Maintained existing correct configurations that already had the http:// prefix

This change affects the following services:

• frontend
• frontend-proxy
• checkout

The update ensures proper service-to-service communication and should resolve the STATUS_CODE_ERROR issues currently being experienced.

Related errors:

• frontend_status_code_error
• frontend-proxy_status_code_error
• checkout_status_code_error

Testing:

• Verified all service URLs include http:// prefix
• Maintained existing correct configurations
• Ensured consistent URL formatting throughout the configuration