P20.b DiffT
Before 5211acfe95a0c6d82a60e2524b5e46b47fe67a3e
After bb35b941115a0a9f818e8512eebe67c29ee68355
Threshold: ZERO semantic mismatches to declared oracle; ZERO reducer mismatches; all mandatory head assertions PASS. Compare each stream and service/upstream channel independently; ignore only cross-channel arrival interleaving.

NOT_COMPARABLE_TO_BASE: GitWorkflowService.currentBranch is a new method absent from the base. Real Git plus explicitly labelled command/registry adapters exercise the head method.
Declared oracle: null / null / exact unborn branch / null respectively. Empty stdout is adapter-only, not claimed as a natural Git repo state.
HEAD OBSERVATIONS (no fabricated base):
{
  "services": {
    "P20": {
      "assertions": [
        {
          "actual": null,
          "outcome": "PASS",
          "test": "detached-HEAD",
          "variant": "detached-HEAD"
        },
        {
          "actual": "unborn/topic",
          "outcome": "PASS",
          "test": "unborn-symbolic-HEAD",
          "variant": "unborn-symbolic-HEAD"
        },
        {
          "actual": null,
          "outcome": "PASS",
          "test": "non-repository",
          "variant": "non-repository"
        },
        {
          "actual": 0,
          "outcome": "PASS",
          "test": "non-repo skips symbolic-ref",
          "variant": "non-repository"
        },
        {
          "actual": null,
          "outcome": "PASS",
          "test": "empty-success-is-null",
          "variant": "controlled-empty-stdout"
        }
      ],
      "branchProbeChannel": [],
      "checkpoints": [],
      "clockAdvances": [],
      "finalResultsAndObservations": [
        {
          "kind": "result",
          "value": null,
          "variant": "detached-HEAD"
        },
        {
          "kind": "result",
          "value": "unborn/topic",
          "variant": "unborn-symbolic-HEAD"
        },
        {
          "kind": "result",
          "value": null,
          "variant": "non-repository"
        },
        {
          "kind": "result",
          "value": null,
          "variant": "controlled-empty-stdout"
        }
      ],
      "invalidationChannel": [],
      "localReadChannel": [],
      "mutations": [],
      "pullChannel": [],
      "reconnects": [],
      "rpcStarts": [],
      "upstreamChannel": []
    }
  },
  "streams": {}
}