chore(node): preserve pre-canonicalization experiment snapshot

Historical working copy retained for audit before consolidation into main. The canonicalized plugin architecture and later fixes already live in main; this snapshot is not a release or a request to restore obsolete source layout.

tests/test_viewer_diagnostics_api.py

@@ -42,6 +42,29 @@ def _request(*, ui_build_id: str | None = None) -> Request:
     return Request({"type": "http", "method": "GET", "path": "/", "headers": headers})
 
 
+def test_scanner_exception_keeps_location_without_private_message_or_locals(
+    tmp_path: Path,
+) -> None:
+    target = configure_scanner_diagnostics(tmp_path / "logs")
+    logger = logging.getLogger(f"{SCANNER_LOGGER_NAME}.test")
+    private_detail = "synthetic-private-runtime-detail"
+    try:
+        raise ValueError(private_detail)
+    except ValueError:
+        logger.exception("Camera activation failed")
+    for handler in logging.getLogger(SCANNER_LOGGER_NAME).handlers:
+        handler.flush()
+    serialized = target.read_text(encoding="utf-8").splitlines()[-1]
+    document = json.loads(serialized)
+    assert document["exception_type"] == "ValueError"
+    assert document["exception_site"].startswith("test_viewer_diagnostics_api.py:")
+    assert document["exception_site"].endswith(
+        ":test_scanner_exception_keeps_location_without_private_message_or_locals"
+    )
+    assert private_detail not in serialized
+    assert str(Path(__file__).parent) not in serialized
+
+
 def test_private_scanner_diagnostics_are_durable_structured_and_bounded(
     tmp_path: Path,
 ) -> None:
@@ -67,6 +90,19 @@ def test_private_scanner_diagnostics_are_durable_structured_and_bounded(
             "device_write_confirmed": False,
             "ble_att_error_code": 4,
             "ble_att_error_name": "INVALID_PDU",
+            "resolved_write_mode": "with_response",
+            "max_write_without_response_size": 253,
+            "mtu_size": 256,
+            "frame_length": 99,
+            "write_characteristic_properties": ["read", "write"],
+            "scan_elapsed_ms": 7300,
+            "scanner_start_ms": 31,
+            "initial_window_ms": 6000,
+            "first_candidate_ms": 7240,
+            "scan_extended": True,
+            "candidate_count": 4,
+            "likely_k1_candidate_count": 1,
+            "discovery_generation": 2,
             "helper_stage": "compile",
             "helper_elapsed_ms": 34720,
             "camera_source_id": "sensor.camera.right",
@@ -126,6 +162,19 @@ def test_private_scanner_diagnostics_are_durable_structured_and_bounded(
     assert document["device_write_confirmed"] is False
     assert document["ble_att_error_code"] == 4
     assert document["ble_att_error_name"] == "INVALID_PDU"
+    assert document["resolved_write_mode"] == "with_response"
+    assert document["max_write_without_response_size"] == 253
+    assert document["mtu_size"] == 256
+    assert document["frame_length"] == 99
+    assert document["write_characteristic_properties"] == ["read", "write"]
+    assert document["scan_elapsed_ms"] == 7300
+    assert document["scanner_start_ms"] == 31
+    assert document["initial_window_ms"] == 6000
+    assert document["first_candidate_ms"] == 7240
+    assert document["scan_extended"] is True
+    assert document["candidate_count"] == 4
+    assert document["likely_k1_candidate_count"] == 1
+    assert document["discovery_generation"] == 2
     assert document["helper_stage"] == "compile"
     assert document["helper_elapsed_ms"] == 34720
     assert document["camera_source_id"] == "sensor.camera.right"