chore: agentic upgrade

.agents/skills/react-best-practices/SKILL.md

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+---
+name: react-best-practices
+description: Use when writing, reviewing, or refactoring React/Next.js code in this repository, especially components, App Router pages, Server Actions, data fetching, bundle optimization, render performance, hydration, or UI responsiveness work.
+---
+
+# React Best Practices
+
+## Overview
+
+Apply Vercel's React and Next.js performance guidance to this repository. The upstream skill was inspected as a full directory, including `SKILL.md`, `README.md`, `metadata.json`, the generated `AGENTS.md`, and all source rule files under `rules/`.
+
+## How to Use
+
+Start with the highest-impact category that matches the task:
+
+1. **Eliminating Waterfalls:** parallelize independent async work, defer awaits until needed, start promises early, and use Suspense boundaries deliberately.
+2. **Bundle Size Optimization:** avoid broad imports where Next cannot optimize them, use `next/dynamic` for heavy UI, defer third-party client libraries, and keep dynamic paths statically analyzable.
+3. **Server-Side Performance:** authenticate Server Actions like public API endpoints, avoid mutable request-scoped module state, minimize RSC-to-client serialization, dedupe per request with `React.cache()`, and hoist static I/O.
+4. **Client Data & Rendering:** dedupe global listeners and requests, use passive scroll listeners, avoid derived-state effects, narrow effect dependencies, move interaction logic into handlers, and avoid inline component definitions.
+5. **Hot Path JavaScript:** use early returns, `Set`/`Map` lookups, index maps, cached property reads, immutable `toSorted()`, and combined iterations only where the path is performance-sensitive.
+
+For this Next/FSD repo, preserve the existing layer boundaries and public `index.ts` APIs while applying these patterns.
+
+## References
+
+- Full compiled guide: `references/vercel-react-best-practices-full.md`
+- Source rules: `references/rules/*.md`
+- Rule categories and impact: `references/rules/_sections.md`
+- Upstream metadata and maintenance notes: `references/upstream/`
+
+Read only the relevant rule files for the task. Use the compiled guide when a broader review needs cross-category context or examples.