Task 4.2: JSON-LD Context Design

**Epic**: #314
**Phase**: Phase 4

### Description
Design JSON-LD context for Morphir IR.

### Activities
1. Design JSON-LD context
2. Create context file
3. Create examples
4. Validate

### Deliverables
- [ ] morphir-context.jsonld
- [ ] JSON-LD examples (10+)
- [ ] Conversion guide

**Effort**: 3 days