Function validate_wasm_config 

pub fn validate_wasm_config(
    service_name: &str,
    spec: &ServiceSpec,
) -> Result<(), ValidationError>

Validate WASM configuration for a single service

Checks:

• WASM config should not be present on non-WASM service types
• min_instances <= max_instances
• max_memory format validation
• Capability restriction validation (users can only restrict from defaults, not grant)
• WasmHttp must have at least one HTTP endpoint (if endpoints exist)
• Preopens must have non-empty source and target

Errors

Returns a validation error if the WASM configuration is invalid.