Improve app navigation and settings by adding new translations

Update i18n files for English and German, and refactor BottomNavigation and Settings components to use translated strings for navigation and settings options.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ceced2fc-aa46-458d-ba87-ddd4b7bb1518
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/659922a9-0087-461c-90dd-6d9a58b81d4d/ceced2fc-aa46-458d-ba87-ddd4b7bb1518/un1X8jl

client/src/i18n/locales/en.json

@@ -6,6 +6,7 @@
   "navigation": {
     "tasks": "Tasks",
     "calendar": "Calendar",
+    "create": "Create",
     "kanban": "Kanban",
     "settings": "Settings"
   },
@@ -88,11 +89,13 @@
     },
     "appearance": {
       "title": "Appearance",
-      "description": "Customize the look and feel"
+      "description": "Customize the look and feel",
+      "themeToggle": "Theme toggle available in the header"
     },
     "templates": {
       "title": "Project Templates",
-      "description": "Use templates to quickly create projects"
+      "description": "Use templates to quickly create projects",
+      "accessInfo": "Access templates from the navigation menu"
     }
   },
   "projectTemplate": {