fix: Bump @serverlessworkflow/sdk-typescript to 1.0.3-alpha3 to pick up DSL version validation fix

[lornakelly]

Description

A bug in the TypeScript SDK (serverlessworkflow/sdk-typescript#266) caused valid 1.0.x workflows to fail validation. When the SDK was built against schema version 1.0.3, validating a workflow with document.dsl set to an earlier patch (e.g. 1.0.0) returned:

The DSL version of the workflow '1.0.0' doesn't match the supported version of the SDK '1.0.3'.

This ticket covers consuming that fix in the editor by upgrading the SDK dependency to 1.0.3-alpha3.

Motivation

The editor surfaces SDK validation results to users, so this bug means anyone authoring a perfectly valid 1.0.x workflow gets a validation error in the UI. Pulling in the fix removes the false positives and restores correct validation behaviour for the full 1.0.x range.

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.