[7.3] Story: Create Migration Guide

## Description

Document how to migrate from local components to shared library.

**Parent Issue:** #EPIC_7

### Sub-Tasks
- [ ] Write step-by-step migration process
- [ ] Create prop API mapping tables
- [ ] Document common issues and solutions
- [ ] Add before/after code examples
- [ ] Include per-app specific notes

### Notes
* See detailed Pager example in SHARED_COMPONENT_LIBRARY_PLAN.md