fix: Cryptic error while trying to activate a workflow with Linear trigger

[everettbu]

Mirror of n8n-io/n8n#26159
Original author: app/github-actions

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Summary

Fixes NODE-4466: Cryptic error while trying to activate a workflow with Linear trigger

When activating a workflow with a Linear trigger using credentials that lack admin permissions, the error message was confusing and didn't indicate that the issue was related to Linear's webhook creation requirements. Users were misinterpreting it as an n8n access control problem.

Changes

• Modified GenericFunctions.ts to prepend "Linear API error:" to error messages from the Linear API
• Added logic to preserve and pass through Linear's userPresentableMessage field in error descriptions
• Added check to prevent re-wrapping already formatted NodeApiError instances
• Created regression test to ensure error messages clearly identify Linear as the source

Test Plan

• Regression test passes (LinearTrigger.node.test.ts)
• Existing tests pass (GenericFunctions.test.ts)
• Typecheck passes
• Lint passes

Related Issues

• Linear: https://linear.app/n8n/issue/NODE-4466
• This includes the regression test from the reproduction step

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🤖 Generated by Flaky (automated bug reproduction + fix)