Add ability to manage task labels and create project templates

Refactors the settings page to include CRUD operations for task labels, integrates template creation navigation, and removes the appearance section.

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

client/src/i18n/locales/en.json

@@ -172,15 +172,31 @@
       "english": "English",
       "german": "German (Deutsch)"
     },
-    "appearance": {
-      "title": "Appearance",
-      "description": "Customize the look and feel",
-      "themeToggle": "Theme toggle available in the header"
+    "labels": {
+      "title": "Task Labels",
+      "description": "Create and manage labels to organize your tasks",
+      "createLabel": "Create Label",
+      "createNewLabel": "Create New Label",
+      "editLabel": "Edit Label",
+      "labelNamePlaceholder": "Label name",
+      "cancel": "Cancel",
+      "create": "Create",
+      "update": "Update",
+      "loading": "Loading labels...",
+      "noLabels": "No labels yet",
+      "noLabelsDescription": "Create your first label to organize your tasks by color and category.",
+      "deleteConfirm": "Are you sure you want to delete this label? This action cannot be undone.",
+      "created": "Label created",
+      "createdDescription": "Your label has been created successfully.",
+      "updated": "Label updated",
+      "updatedDescription": "Your label has been updated successfully.",
+      "deleted": "Label deleted",
+      "deletedDescription": "Your label has been deleted successfully."
     },
     "templates": {
       "title": "Project Templates",
       "description": "Use templates to quickly create projects",
-      "accessInfo": "Access templates from the navigation menu"
+      "manageTemplates": "Manage Templates"
     }
   },
   "projectTemplate": {