fix(observability): router conflict, logout button, missing i18n

- Fix chi duplicate Route() panic by consolidating read/write routes
  into single Route blocks with nested admin Group
- Add logout button to sidebar with token cleanup
- Add missing settingsAuth.password i18n key

web/src/lib/i18n/en.json

@@ -9,7 +9,8 @@
     "deploy": "Deploy",
     "proxies": "Proxies",
     "events": "Events",
-    "settings": "Settings"
+    "settings": "Settings",
+    "logout": "Log out"
   },
   "dashboard": {
     "title": "Dashboard",
@@ -311,7 +312,8 @@
     "createFailed": "Failed to create user",
     "deleteFailed": "Failed to delete user",
     "deleteConfirm": "Are you sure you want to delete this user?",
-    "usernameRequired": "Username and password are required"
+    "usernameRequired": "Username and password are required",
+    "password": "Password"
   },
   "login": {
     "title": "Docker Watcher",