docs: add comprehensive Electron/React migration architecture analysis

Add detailed architectural analysis for migrating from Python/Tkinter
to modern Electron/React/TanStack Router/shadcnUI stack.

Contents:
- Current architecture analysis (features, limitations, data models)
- Proposed modern architecture with detailed technology stack
- Component architecture and file structure
- API design (REST endpoints, WebSocket events)
- State management strategy (Zustand + TanStack Query)
- 6-phase migration plan (24 weeks)
- Performance optimization strategies
- Security considerations
- Testing strategy
- Deployment and auto-update configuration
- Risk assessment and mitigation

This document provides a complete roadmap for building a production-ready
Warehouse Analysis System with modern web technologies while maintaining
all existing features and improving UX/performance.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: codewizdave