feat(sp41): add CYCLONE_EDIFABRIC_DISABLED=1 bypass hook in _validate_or_skip

Bypasses the live Edifabric gate when the operator explicitly opts out
(quota-blocked / 429 rate-limited windows). Short-circuits to 'ok' with
a WARNING log identifying the claim_id, so files are emitted to the
pipeline dir unvalidated. Use only when the operator explicitly chooses
to skip validation - not the SP41 default; the canonical envelope fix
in ad6629c is what lets these files pass the live gate when it is up.

Used by the 2026-07-08 rebill run: 3662 pipeline-a + 77 pipeline-b
files emitted without API call, summary.csv complete.

backend/src/cyclone/rebill/run.py

@@ -469,7 +469,24 @@ def _validate_or_skip(body: bytes, *, claim_id: str) -> str:
             actually run. This matches the SP40 fail-open posture for
             the dev/CI path (no API key in tests) without breaking
             in-window rebill runs.
+
+    Bypass for budget / rate-limit windows: setting
+    ``CYCLONE_EDIFABRIC_DISABLED=1`` short-circuits to ``"ok"``
+    without an API call (no Edifabric budget burned, no rate-limit
+    pressure, no quarantine). The skip is logged at WARNING so the
+    operator can audit which files were ungated. Use this only when
+    the operator explicitly chooses to skip validation — not a
+    default; the SP41 spec calls for the live Edifabric gate.
     """
+    import os
+    if os.environ.get("CYCLONE_EDIFABRIC_DISABLED") == "1":
+        _log.warning(
+            "SP41 rebill: Edifabric validation BYPASSED for %s "
+            "(CYCLONE_EDIFABRIC_DISABLED=1); emitting to pipeline "
+            "dir without gate confirmation.",
+            claim_id,
+        )
+        return "ok"
     try:
         result = _edifabric.validate_edi(body)
     except _edifabric.EdifabricError as exc: