Documentation and cleanup. Guidance around the coordination backend was sharpened to emphasize that it is a hard requirement rather than an optional dependency. On the code side, a leftover compatibility check for contextlib.nested was dropped, removing 40 lines of dead Python 2-era scaffolding.

Tooling and CI. Several small tox refinements landed: redundant passenv entries and a manual VIRTUAL_ENV injection were removed, and the functional-test job gating was retuned to run on job-config updates while skipping runs triggered only by unit-test code changes.

Branching. The stable/2026.2 branch was cut, with master, .gitreview, and TOX_CONSTRAINTS_FILE updated for the new development cycle.