docs: add unreleased section and changelog rule

Author: AbdelrahmanBayoumi

AGENT.md

@@ -82,3 +82,4 @@ This repository contains `arabic-services`: a zero-runtime-dependency TypeScript
 ## Commit & PR Conventions
 
 - Commit messages and PR titles must follow `CONTRIBUTING.md` using the Conventional Commits specification (`feat:`, `fix:`, `docs:`, `test:`, `refactor:`, `chore:`).
+- Document new features, bug fixes, or tooling updates under `## [Unreleased]` in `CHANGELOG.md` following Keep a Changelog conventions.

CHANGELOG.md

@@ -1,5 +1,15 @@
 <h1 align=center>📜 Changelog - سجل التغيير</h1>
 <p align=center>All notable changes to this project will be documented in this file.</p>
+## [Unreleased]
+
+### Added
+- Integration tests for CJS, ESM, and browser UMD artifacts.
+- Arabic NLP boundary and ReDoS resilience test suites.
+- Direct CDN links (jsdelivr & unpkg) and GitHub release bundle guide in documentation.
+
+### Changed
+- Relocated standalone browser demo to `examples/browser/index.html`.
+- Unified CI workflow across Node.js 22.x and 24.x with ESLint.
 
 ## [1.1.0](https://github.com/Seen-Arabic/Arabic-Services-JavaScript/releases/tag/v1.1.0) - 2026-10-14 (03 Jumada al-Awwal 1448)