Spike: Evaluate embedded code editor

[lornakelly]

Description

Evaluation of the embedded code editor for the text pane. Compare editor options like Monaco, CodeMirror 6 etc. Add findings to the ticket and recommend one to the team and community for review.

Motivation

The editor choice is an open ADR question and the wrong choice is expensive to reverse because the VS Code extension reuses the same engine

Proposed Implementation

No response

Definition of Done

• Implementation: Fully implemented according to the Serverless Workflow spec.
• Unit Tests: Comprehensive unit tests are included and passing.
• Integration Tests: Verified within the monorepo and target environments (Web/VS Code).
• Documentation: Updated README.md, ADRs, or official docs.
• Performance: No significant regression in editor responsiveness.
• Accessibility: UI changes comply with accessibility standards.