Fix red develop 4514b57daa55

The merge lane found `develop` red at `4514b57daa557a54bd52071683ea811d2e144d08` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `tests/test_cross_org_isolation.py::test_every_path_parameter_is_swept_or_named` - `api-unit-dc-test` The whole gate log: artifact `11862` on lane task 11104. Make `develop` pass its full gate again. Open a PR as usual: the merge lane merges a PR that fixes some of these and adds no failure even while `develop` is red.

Fixed red develop: the cross-org sweep test failed because the template image `asset_id` route param (Task 11071) was not registered. Added it to _UNSEEDED_PARAMS, citing its 404 proof test. Quick gate green; PR #7274 queued to the merge lane. Memory: none applied.