Floating drift mode

Pinned mode answers "does the documented claim still match its evidence pin?". Floating mode answers "does current upstream still have the same capability shape?" — the same gate runs with one or more inputs overridden to their moving branch or current release.

The exact --override-input invocations, including the npm surfaces whose version must be resolved first, are listed in the domain README.

Floating red is review evidence, not automatically an upstream regression. A missing required string may mean an API moved or was renamed, and a red absence check says the previously missing capability may now exist: inspect upstream and update the skill and matrix instead of weakening the check.

Scheduled drift run

.github/workflows/fixpoint-evidence-drift runs the full floating invocation monthly (17 6 1 * *) and on workflow_dispatch. It resolves the current @evolution-sdk/evolution and @meshsdk/core versions, runs nix flake check with every input overridden, and on failure opens — or comments on — an open issue titled "Fixpoint evidence drift detected" with the full log attached.