Fix red develop 364fff1ddd59

The merge lane found `develop` red at `364fff1ddd59b96d4e378e7df79b200b2f25a0a8` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `tests/test_agent_router_ledger_stats.py::test_the_version_names_the_ledger_and_the_day` - `api-unit-dc-test` The whole gate log: artifact `14791` on lane task 12976. 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 ledger version test captured NOW at import and broke when the gate crossed UTC midnight; it now pins ledger_stats.utcnow. Quick gate green; PR #7811 queued to the merge lane. Memory: none applied.