ACL user inventory goes stale after create and delete (no server-page refresh)

## Problem

On the ACL page 用户管理 tab, creating or deleting a user only mutates the local page array. The server-paginated total is never updated and no refetch is triggered, so:

- Creating a user with a full page prepends the new row and silently pushes the previously-last row out of view; the pagination total keeps its stale value.
- Deleting the last row on the last page leaves an empty page: the total stays too high, and the empty-page auto-correction (which lives inside the fetch effect) never runs because nothing refetches.

## Evidence / source

- Code inspection of the current `rocketmq-studio` branch (base commit 36126024): `acl.tsx` `handleUserSubmit` (create branch, `setUsers((prev) => [normalizeUser(created), ...prev])`) and `handleDeleteUser` (`setUsers((prev) => prev.filter(...))`) touch neither `userTotal` nor any refresh key, while the sibling rules tab bumps `ruleRefreshKey` after its mutations.
- Deterministic Vitest reproduction in `AclPage.test.tsx`: `reloads the server user page after creating an ACL user` and `reloads the server user page after deleting one ACL user` both fail on the unfixed source (`pageAclUsers` called once instead of twice).

## Impact

Wrong pagination totals, rows that disappear from view after create, and an unrecoverable empty page after deleting the last row on the last page — until the user manually changes the page or refetches.

## Expected behavior / acceptance criteria

- After a successful user create or delete, the authoritative server page is reloaded (same pattern as the rules tab).
- Pagination totals stay synchronized with the server.
- An emptied page falls back to the previous page via the existing correction logic.
- Regression coverage for both mutation paths; they must fail on the unfixed code.

## Related work

- #2680 (closed) fixed the same defect class for Topic and Consumer Group deletion; the ACL user inventory was outside that scope and also exposes the create-path symptom.

## PR

PR #3300 (includes the fix and two regression tests).

Start in acl.tsx by reading handleUserSubmit and handleDeleteUser, then run the two named Vitest cases in AclPage.test.tsx. Compare the user-tab behavior with the sibling rules-tab refresh pattern. Done means both mutation paths reload the server page, totals stay current, and deleting the last row allows the existing empty-page correction to run.

Written by the indexing model from the issue text.