Production-grade front-end engineering: semantic HTML5, scalable CSS architecture, responsive design, performance optimization, and security hardening.

```dart // Dart side class NativeApi { static const _channel = MethodChannel('com.app/native_api'); static Future getDeviceId() async { try { return await _channel.invokeMethod('getDeviceId'); } on PlatformException catch (e) { d

| Concern | Key API / Pattern | |---|---| | App Router layouts | `app/layout.tsx`, `template.tsx` | | Loading / Error UI | `loading.tsx`, `error.tsx`, `global-error.tsx` | | Parallel routes | `@folder` slot convention | | Intercepting routes | `(.)`

--- name: python-mastery category: coding description: Comprehensive Python mastery skill covering architecture, idiomatic code, design patterns, security, testing, performance, and deployment for production-grade Python applications. version: 1.0.0

React mastery: hooks deep dive, state management, component patterns, security, performance optimization, and testing.

Production database mastery — MySQL/MariaDB, PostgreSQL, Redis, backup strategies, replication, and query optimization

Production server hardening — SSH, fail2ban, UFW/iptables, auditd, kernel tuning, intrusion detection, and compliance

### Cache Strategy Decision Tree ``` Need caching? ─┬─ Read-heavy, static data ──→ Cache-Aside (lazy load) ├─ Write-heavy, must be fresh ──→ Write-Through (sync write) ├─ Batch writes acceptable ──→ Write-Behind (async

Provision and sync Hermes Agent to child VPSes for parallel work delegation.

Deploy and maintain the WhatsApp Chat Viewer — a Flask web app that reads Hermes session transcripts and displays them in a WhatsApp Web-like UI. Includes WhatsApp Bridge API integration for group nam