[Bug]: ChainService importChain fails when JSON missing steps

[SSJane]

Bug Description

When importing a valid JSON that lacks the steps property, chainService.importChain() throws a TypeError: Cannot read properties of undefined (reading 'map') instead of the expected Error("Invalid chain data").

Steps to Reproduce

1. Create a JSON file without a steps field:

   {
     "name": "sample chain"
   }

2. Call :

await chainService.importChain(validJsonWithoutSteps);

3.Observe the thrown error.

Expected Behavior

The function should throw a controlled error:

Error: Invalid chain data

Actual Behavior

The function throws a TypeError:

Cannot read properties of undefined (reading 'map')

Environment

Vitest/ui v4.0.5
Vitest/coverage-v8 v4.0.4

Node.js v22.2.0

OS: Windows 11

File: src/lib/chain-service.ts

Test file: chain-service.test.ts

Screenshots

Additional Context

No response