feat: Bump sdk package and remove temporary workaround

[lornakelly]

Description

Once open-workflow-specification/sdk-typescript#289 is merged, update our SDK dependency and adapt the diagram editor to the new changes and remove the workaround introduced here

The sdk should handle validation and the added stories from temporary workaround should still be clean of errros once workaround is removed

Motivation

Index-based node IDs currently churn whenever a sibling task is added or removed, which breaks anything in the editor that keys off node ID stability. The new name-path ID scheme fixes that at the source. Since this is a breaking SDK change, we need a deliberate upgrade pass rather than a silent bump.

Proposed Implementation

No response

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.

[lornakelly]

@handreyrc We are adding a fix to sdk so hold off on this until we get to alpha6

[lornakelly]

Waiting on specification changes so we can update the sdk package