UI identity groups pagination returns 404 on page 2+

[alexandrust88]

Describe the bug

The Vault UI displays a "404 Not Found" error when navigating to page 2 (or subsequent pages) of identity groups listing, even though groups exist on those pages.

Error message:
404 Not Found Sorry, we were unable to find any content at /vault/access/identity/groups?page=2. Double check the url or go back home.

To Reproduce

Steps to reproduce the behavior:

1. Run vault server -dev
2. Run the following to create 300 groups:

export VAULT_ADDR=http://127.0.0.1:8200
export VAULT_TOKEN=root
for i in $(seq 1 300); do
  vault write identity/group name="test-group-$(printf '%03d' $i)" policies="default"
done
Open Vault UI at http://127.0.0.1:8200/ui
Login with root token
Navigate to Access > Identity > Groups
Page 1 loads correctly showing first 100 groups
Click page 2 in pagination controls
See error: 404 Not Found
Expected behavior Page 2 should display groups 101-200, page 3 should display groups 201-300. Environment:
Vault Server Version (retrieve with vault status): 1.20.4
Vault CLI Version (retrieve with vault version): 1.20.4
Server Operating System/Architecture: linux/amd64 (Docker), also tested on Kubernetes
Vault server configuration file(s):

# Dev mode - no config file needed for reproduction
# vault server -dev
Additional context Reproduction confirmed on both Vault OSS 1.20.4 and Vault Enterprise 1.20.4-ent.
Page 1 displays correctly with 100 groups
Total groups confirmed via API: vault list identity/group/id returns all groups
The URL /vault/access/identity/groups?page=2 appears in browser but returns 404
Vault CLI and API work correctly - only UI pagination is broken
Likely cause: The Ember.js router for /vault/access/identity/groups doesn't properly handle the page query parameter. Workaround: Use vault list identity/group/id via CLI.