test: gate V1 side files and V3 legacy receipts; early output rejection

- analyze_jet_cv_continuation: samples are analyzed only if the sibling
  re*_s*.json receipt is the same case with run_status COMPLETE and
  source_recheck UNCHANGED; receipts without run_status (pre-recheck
  runners) are refused unless --legacy-receipts, and labelled
  LEGACY_NO_FINAL_SOURCE_RECHECK. Results carry receipt_gate.
- V3: receipts are schema 2 and need source_recheck UNCHANGED; a missing
  recheck is accepted only for frozen-mode schema 1 receipts whose
  run_case.py hash is one of the pre-recheck runners (9805383, 2cf9853,
  db3d098; hashes checked against git history in a test).
- V1/V3 refuse --output inside the checkout before source checks or CUDA
  (shared source_provenance.reject_output_inside).
- A failing recheck is recorded as RECHECK_FAILED (still invalid); the
  in-run V1 receipt write is tmp+replace.
Negative host tests for each gate. No threshold, solver or evidence edits.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/validation/run_jet_circle_cv.py

@@ -592,9 +592,9 @@ def run_case(c, ctx, output, provenance, continuation=False):
                     physics_validation_pass=False,
                     precision="FP32 evolution, FP64 host diagnostics",
                 )
-                (output / f"re{c['re_d']}_s{c['scale']}.json").write_text(
-                    json.dumps(payload, indent=2) + "\n"
-                )
+                receipt = output / f"re{c['re_d']}_s{c['scale']}.json"
+                Path(str(receipt) + ".tmp").write_text(json.dumps(payload, indent=2) + "\n")
+                Path(str(receipt) + ".tmp").replace(receipt)
                 print(
                     json.dumps(
                         dict(
@@ -670,6 +670,8 @@ def main():
     ):
         p.error("Root must select one verified idle GPU via CUDA_VISIBLE_DEVICES")
     repo = a.repo.resolve()
+    from source_provenance import reject_output_inside
+    reject_output_inside(a.output, repo)
     provenance = source_identity(repo, a.current_checkout)
     sys.path.insert(0, str(repo / "src"))
     import CelerisLab