chore: Upgrade TypeScript to 7 once supported by Volar #508

Requires: volarjs/volar.js#328

Description

Upgrade OWS Editor from TypeScript 6 to TypeScript 7 once the Volar packages used by the editor officially support it.

This is a follow-up to #507, which temporarily downgrades TypeScript to 6 due to Volar 2.x's typescript: <7 peer dependency restriction.

Motivation

TypeScript 6 is a temporary compatibility solution. Once Volar supports TypeScript 7, we should restore the latest major version and remove the Dependabot restriction introduced in #507.

Proposed Implementation

• Upgrade Volar and TypeScript to ^7.0.0 , maintaining a single TypeScript version.

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).
• Performance: No significant regression in editor responsiveness.

Additional references

• OWS Editor bug: TypeScript 7 conflicts with Volar 2.4.30 peer dependencies #507: bug: TypeScript 7 conflicts with Volar 2.4.30 peer dependencies #507
• Volar TypeScript compatibility restriction: volarjs/volar.js@ddef86e
• Volar TypeScript 7.1 work (v3): build: build and type-check with TypeScript 7.1 volarjs/volar.js#328