refactor: remove GitHubStatsSection component and its mock data

fix: remove Homelab link from Menu component

i18n: update TimelineSection to use translation keys for experience items

i18n: switch to loading translations from backend instead of hardcoded

style: add custom variant for dark mode in index.css

style: clean up unused CSS variables and classes in output.css

config: update tailwind.config.js to use ES module syntax

config: include env.d.ts in tsconfig.json for type definitions

env.d.ts

@@ -0,0 +1,12 @@
+/// <reference types="vite/client" />
+
+interface ImportMetaEnv {
+  readonly VITE_GITHUB_TOKEN: string;
+  readonly VITE_EMAILJS_SERVICE_ID: string;
+  readonly VITE_EMAILJS_TEMPLATE_ID: string;
+  readonly VITE_EMAILJS_USER_ID: string;
+}
+
+interface ImportMeta {
+  readonly env: ImportMetaEnv;
+}