CALM VS Code Plugin Updates

## Feature Proposal
Update CALM VS Code Plugin to use CALM Hub technology ( React Flow ) and allow editing capability of diagrams in VS Code

### Target Project:
VS Code Plugin

### Description of Feature:

- Edit CALM Diagrams using VS Code CALM Plugin
- Export CALM Diagrams as SVG ( WYSIWYG )
- Workspace level Building Blocks, Standards & Guidelines Sourcing in Plugin
- Validate CALM Architecture Digram for Controls compliance
- Trigger CALM Agent to produce Solution Design Specification using CALM Agent

### User Stories:
As user i wanted to use vs code plugin of CALM to author, manage & maintain CALM Architecture diagrams in VS Code.

### Current Limitations:
Not able to edit CALM Diagrams in VS Code Extention

### Proposed Implementation:
...provide details of the intended implementation approach, including:
- Technical design considerations
- API changes (if applicable)
- Data model changes (if applicable)
- Dependencies on other components

### Alternatives Considered:
...what other approaches were considered and why were they rejected?

### Testing Strategy:
...how will this feature be tested? Include unit, integration, and any other testing considerations...

### Documentation Requirements:
...what documentation will need to be created or updated?

### Implementation Checklist:
- [ ] Design reviewed and approved
- [ ] Implementation completed
- [ ] Tests written and passing
- [ ] Documentation updated
- [ ] Relevant workflows updated (if needed)
- [ ] Performance impact assessed

### Additional Context:

Start with the VS Code Plugin target and the React Flow dependency named in the proposal. Define the technical design, API or data-model needs, dependencies, and testing approach before implementation. Done requires the listed editing, SVG export, workspace sourcing, validation, and CALM Agent capabilities to be implemented, tested, and documented.

Written by the indexing model from the issue text.