Introduce a dynamic color scheme that adapts to user mood and time

Adds ThemePage with adaptive theme control and localization in i18n files.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: c5f0c281-8dd8-4846-b452-4a07bcd21062
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/9777c70b-fc38-4831-8d6b-78dfffe041b0/10c277b8-60f1-4b7d-855d-8ed2071cad3f.jpg

client/src/components/layout/Sidebar.tsx

@@ -19,7 +19,8 @@ import {
   Zap,
   Monitor,
   UserCheck,
-  Focus
+  Focus,
+  Palette
 } from "lucide-react";
 
 interface SidebarProps {
@@ -63,6 +64,11 @@ const getNavigation = (t: any) => [
     href: "/focus",
     icon: Focus,
   },
+  {
+    name: t('navigation.themes'),
+    href: "/themes",
+    icon: Palette,
+  },
 ];
 
 const getManagementNavigation = (t: any) => [