fix(acls): prevent React key collision wiping ACLs on edit (UX-1217, UX-1219)

[c-julin]

Summary

Fixes the customer-facing ACL wipe bug (UX-1217) by resolving the underlying React key collision (UX-1219) in create-acl.tsx.

Parent epic: UX-1198 REST-to-Connect RPC Migration. Split out from PR #2382 so this lands independently and fast to customers who hit UX-1217.

The bug

frontend/src/components/pages/security/acls/create-acl.tsx:777 used a hardcoded useRef(2) for the rule ID counter. In edit mode, propRules arrive with IDs 0, 1, 2, 3, ... from an external counter. When a user then adds a new rule via addRule(), the new rule gets id=2 — colliding with an existing rule's ID.

React key collisions in list reconciliation can silently corrupt form state: field values bleed between rows, operation settings swap, state updates target the wrong row. In the specific customer flow from UX-1217, this caused ACLs to be lost when editing.

The fix

Initialize the counter from Math.max(...propRules.map(r => r.id)) + 1 when editing, else keep the fresh-create default of 2.

const ruleIdCounter = useRef(
  propRules && propRules.length > 0
    ? Math.max(...propRules.map((r) => r.id)) + 1
    : 2
);

Regression test

Added frontend/tests/test-variant-console/acls/acl-edit-preserves-rules.spec.ts:

• Creates ACLs, opens edit, adds a consumer-group rule, saves, asserts all rules preserved
• Currently skipped — the AclPage.configureRule page-object helper can't reliably target multi-card forms with same resourceType. Test shape is correct; helper needs a follow-up extension. Tracked in UX-1217 handoff comments.

Stats

• 2 files changed (1 src fix + 1 new test), 150 insertions, 2 deletions

Test plan

• bun run type:check passes
• bun run lint on changed files — no new errors introduced (pre-existing nursery warnings in create-acl.tsx unchanged)
• Manual: re-run the UX-1217 customer repro against this branch and verify ACLs are preserved

Related

• Split from PR refactor: migrate users, ACLs, quotas from REST to Connect RPC #2382 (UX-1199 Phase 1 REST-to-Connect migration) for faster customer delivery. The same fix is also included in that PR.
• Closes UX-1219
• Likely closes UX-1217 pending customer confirmation