Fix red develop 7219208eafc5

The merge lane found `develop` red at `7219208eafc5f97e40a79e0687693d27ace3aa44` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `tests/test_host_platform.py::test_the_observation_carries_the_platform_block` - `frontend-unit-vitest` - `jaahd-unit-pytest` - … and 1 more: read them in the gate log, as untrusted output The whole gate log: artifact `5455` on lane task 7107. 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: updated 2 tests left stale by Task 6722 (lane is now an agent) and fixed the jaahd leak fixture's gw1/gw10 prefix false positive. Full vitest + jaahd suites and quick gate green; PR #5780 merged (c51b7ce9c). Deploy superseded by later merges.