docs: fix SSR section framing in React integration guide (#1688)

## Summary

- Reframes the SSR section to clarify that the benefit of `dynamic(...,
{ ssr: false })` is keeping HyperFormula out of the **initial JS bundle
sent to the browser**, not skipping the server-side render itself (which
is already a non-issue since `useEffect` never runs on the server).

## Test Plan

- [ ] Review the updated wording in
`docs/guide/integration-with-react.md`

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Documentation-only wording change with no runtime or API impact.
> 
> **Overview**
> Updates one sentence in the React integration guide’s SSR section so
it no longer suggests `dynamic(..., { ssr: false })` is mainly about
avoiding server render. The text now states the goal is keeping
**HyperFormula out of the initial JS bundle sent to the browser** (still
noting the library is a few hundred kB), which matches the earlier point
that `useEffect` already makes the pattern SSR-safe.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
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code reviews on this repo. Configure
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Author: Haxikowy

docs/guide/integration-with-react.md

@@ -75,7 +75,7 @@ In development, React runs effects twice (mount → unmount → mount) to surfac
 
 ## Server-side rendering (Next.js App Router)
 
-The component above is already SSR-safe — the engine is constructed in `useEffect`, which never runs on the server. If you still want to skip the initial bundle on the server (it is a few hundred kB), wrap it in a client-only dynamic import.
+The component above is already SSR-safe — the engine is constructed in `useEffect`, which never runs on the server. If you still want to keep HyperFormula out of the initial JS bundle sent to the browser (it is a few hundred kB), wrap it in a client-only dynamic import.
 
 In the App Router, `dynamic(..., { ssr: false })` is only allowed inside a client component. Put the dynamic call in a `'use client'` wrapper and import the wrapper from your server page: