test(billing): preserve entitlement golden across Omi Pro display rename
Backend shard 4 rejects #24367's approved Unlimited → Omi Pro display rename because the legacy entitlement snapshot includes definition.display_name. The complete catalog diff in that PR is revision 12 → 13 and the unlimited_v2 display name; its runtime change is the matching plan-card title. No price identity, allocation, feature, access rule, or billing behavior changed.
Keep the original historical golden untouched and apply only the exact unlimited_v2 / Unlimited → Omi Pro rename to the expected snapshot. The byte comparison still pins all fields, including the new display name, and each price's runtime resolver policy is compared against the same adjusted expectation. Arbitrary display-name changes still fail.
Validation: omi-heavy run -- nice -n 19 env BACKEND_UNIT_TEST_FILE_LIST=<entitlement-tests.txt> BACKEND_PYTEST_WORKERS=1 bash backend/test.sh passed all 58 entitlement-version tests. A separate subscription-restructure shard with BACKEND_PYTEST_MARK_EXPR='not integration' passed all 36 tests, including the Omi Pro catalog title assertions. The complete standard pre-push gate passed, including the shared repository preflight, catalog compiler contract, Pyright, and the 58-test changed shard again. Luna round 1 returned SHIP with no findings. Exact head 2580a5913ebf0068a2694f0fda2c09f9197b28e9 reached terminal CI: 39 success, 25 skipped, 1 neutral in the full check rollup; no failures, pending or cancelled checks. No reruns were needed. This changes tests only; no endpoint or deployment is needed.
Failure-Class: none
This repairs a test expectation for an approved display-name change; it changes no product behavior or entitlement contract and preserves the complete legacy runtime snapshot guard.