MT DEV: NWK loading. MT should stop processing if user error, and inform user

[ikb6]

Problem / Opportunity

When I load a NWK tree with duplicates, MT shows the spinning helix, but underneath, there is an error saying leaf names are duplicated.

Proposed Behavior

MicrobeTrace should stop the helix, and give "Unable to process NWK due to duplication in leaf names. Please re-try after fixing the naming issue."

Feature Area / View

Loading screen

Inputs / Data Shape

NWK

Acceptance Criteria

• Given...
• When...
• Then...

Related Work

• Existing user story:
• Existing bug:
• Cypress coverage:
• Docs/manual: