feat: enterprise hardening - request bodies, radix router, and error …

…into dev/uno

CORE & PERFORMANCE:
- Implement zero-allocation request body parsing in Rust core
- Upgrade router from O(N) linear scan to O(M) Radix Tree
- Optimize binary bridge to support high-throughput body transfers
- Implement buffer pooling for body reads to minimize GC pressure
FEATURES & MIDDLEWARE:
- Add centralized error handling middleware support (app.onError)
- Implement built-in CORS middleware with preflight handling
- Add schema-agnostic validation middleware (Zod/TypeBox compatible)
- Add native support for req.json(), req.text(), and req.body
DEVELOPER EXPERIENCE:
- Provide full TypeScript definitions (index.d.ts)
- Implement self-referencing package exports in package.json
- Add comprehensive examples (REST API, CORS, Validation, Middleware)
SECURITY:
- Add CRLF injection prevention in static response headers
- Implement strict max body size limits (1MB) to prevent DoS
- Fix Rust borrow checker conflicts for safe concurrent body handling

Feature/enterprise hardening