feat: Create the text-editor package #332

Description

Create packages/text-editor (@openworkflowspec/text-editor) as the package foundation for the Monaco-based Open Workflow text editor.

Motivation

Provide the common package infrastructure required to implement a Monaco for Open Workflow text editing.

Proposed Implementation

• Create the @openworkflowspec/text-editor workspace package based on monaco-editor .
• Language-service integration will be implemented separately in: feat: Integrate the language service with Monaco #331
• Inline validation markers are covered by: feat: inline validation markers in the text edit #227
• Storybook implementation to showcase the component

The package should remain private for now.

Definition of Done

• Implementation: Fully implemented according to the Open 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.