Merge the wilm work, act on the five-agent review, verify the launch-path policy on Windows

requirements-dev.in

@@ -10,3 +10,10 @@
 pytest>=7.0
 pytest-flask>=1.2
 pytest-cov>=4.0
+# Parallel test execution. The suite is ~2300 tests whose cost is per-test
+# fixture teardown (create_all/drop_all is ~0.06s each, ~40% of the wall clock)
+# rather than any single slow test, so it parallelises almost linearly: 331s ->
+# 103s on 8 cores, same 2309 passing. NOT in pytest.ini addopts - worker startup
+# is dead weight on the targeted runs that make up most of a working day. Opt in
+# with -n auto when running the whole suite.
+pytest-xdist>=3.5