perf(observatory): avoid duplicate camera verification

tests/test_observatory_worker_http_transport.py

@@ -562,6 +562,7 @@ def test_large_camera_inventory_has_bounded_secure_destination_planning(
 
 def test_http_gateway_packed_camera_epoch_bounds_requests_and_header_timeout(
     tmp_path: Path,
+    monkeypatch: pytest.MonkeyPatch,
 ) -> None:
     job = _job(
         bundle_sha256=hashlib.sha256(b"source-bundle").hexdigest(),
@@ -576,6 +577,35 @@ def test_http_gateway_packed_camera_epoch_bounds_requests_and_header_timeout(
     artifact_requests: list[httpx.Request] = []
     camera_member_requests: list[str] = []
     archive_read_timeouts: list[float] = []
+    secure_directory_calls: list[Path] = []
+    existing_hash_paths: list[Path] = []
+    original_secure_directory = worker_http_transport_module._secure_directory
+    original_hash_local_regular_file = (
+        worker_http_transport_module._hash_local_regular_file
+    )
+
+    def counting_secure_directory(path: Path) -> Path:
+        secure_directory_calls.append(path)
+        return original_secure_directory(path)
+
+    def counting_hash_local_regular_file(
+        path: Path,
+        maximum_bytes: int,
+    ) -> tuple[str, int]:
+        if path.exists():
+            existing_hash_paths.append(path)
+        return original_hash_local_regular_file(path, maximum_bytes)
+
+    monkeypatch.setattr(
+        worker_http_transport_module,
+        "_secure_directory",
+        counting_secure_directory,
+    )
+    monkeypatch.setattr(
+        worker_http_transport_module,
+        "_hash_local_regular_file",
+        counting_hash_local_regular_file,
+    )
     rows = manifest["members"]
     assert isinstance(rows, list)
     camera_member_ids = {
@@ -627,12 +657,43 @@ def test_http_gateway_packed_camera_epoch_bounds_requests_and_header_timeout(
     ) as gateway:
         _cache_claim(gateway)
         stage = gateway.materialize(job)
+        first_materialization_secure_calls = tuple(secure_directory_calls)
+        assert existing_hash_paths == []
+        existing_hash_paths.clear()
+        resumed_stage = gateway.materialize(job)
 
+    assert resumed_stage == stage
     assert archive_read_timeouts == [
         WORKER_HTTP_CAMERA_ARCHIVE_READ_TIMEOUT_SECONDS
     ]
     assert camera_member_requests == []
-    assert len(artifact_requests) == 6
+    assert len(artifact_requests) == 7
+    camera_root = stage.root / "camera"
+    camera_hash_paths = [
+        path for path in existing_hash_paths if path.is_relative_to(camera_root)
+    ]
+    assert len(camera_hash_paths) == 102
+    assert set(camera_hash_paths) == {
+        stage.root / "camera/epoch-1/init.mp4",
+        *(
+            stage.root / f"camera/epoch-1/segments/{sequence}.m4s"
+            for sequence in range(1, 102)
+        ),
+    }
+    assert (
+        sum(
+            path == stage.root / "camera/epoch-1"
+            for path in first_materialization_secure_calls
+        )
+        == 1
+    )
+    assert (
+        sum(
+            path == stage.root / "camera/epoch-1/segments"
+            for path in first_materialization_secure_calls
+        )
+        == 1
+    )
     assert (
         stage.root / "camera/epoch-1/segments/101.m4s"
     ).read_bytes() == b"sealed-camera-segment-101"