docs: add project index pages with categorized listings

docs/en-gb/projects/index.md

@@ -2,4 +2,20 @@
 title: Projects
 ---
 
-Explore awesome projects developed by OnixByte.
+Explore open-source projects developed by OnixByte.
+
+## Libraries & Toolkits
+
+- **[OnixByte Toolbox](/projects/onixbyte-toolbox)** — A development kit for Java applications: AES, hashing, Base64, collection utilities, crypto key loaders, statistical calculators, identity generators, and generic tuples.
+- **[regions4j](/projects/regions4j)** — Type-safe ISO 3166-1 regional metadata as a Java enum with O(1) lookups, E.164 dialling codes, and locale tags.
+- **[Captcha](/projects/captcha)** — A modern Java CAPTCHA generation library with water ripple, fish-eye, and shadow distortion effects.
+- **[Calendar Toolbox](/projects/calendar-toolbox)** — A Java library for creating `.ics` files conforming to the iCalendar specification (RFC 5545).
+
+## Full-Stack Applications
+
+- **[Helix](/projects/helix)** — An enterprise application template with Spring Boot backend and React frontend, featuring JWT auth, RBAC, user and organisation management, and Microsoft Entra ID integration.
+- **[Delta Force Guide](/projects/delta-force-guide)** — A web app providing a searchable library of firearm modification codes for the game _Delta Force: Havvk Ops_, with a React SPA and Spring Boot REST API.
+
+## Vite Plugins
+
+- **[Port Checker](/projects/vite-plugins/port-checker)** — Warns when the Vite dev server listens on a browser-restricted port, preventing silent connection failures.