统一多相机连接与 UART 数据协议

启动时完整连接所有配置相机，移除旧命令与单路数据格式。通过 22 项回归测试、真实 SDK 的 1–4 路录像验证、Ruff 和文档检查。

tests/check_backend.py

@@ -0,0 +1,78 @@
+"""Exercise real SDK instances for 1-4 recorded inputs, without UART/hardware."""
+
+import argparse
+import itertools
+import os
+import sys
+from functools import partial
+from pathlib import Path
+from unittest.mock import patch
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "serial"))
+from finger_api import FingerSensorBank
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--recording", required=True, type=Path)
+    parser.add_argument("--scratch", required=True, type=Path)
+    args = parser.parse_args()
+    scratch = args.scratch.resolve()
+    scratch.mkdir(parents=True, exist_ok=True)
+    os.environ["NUMBA_CACHE_DIR"] = str(scratch / "numba")
+
+    import cv2
+    import numpy as np
+    import orisys
+    from orisys.finger import FingerRuntime
+
+    print(f"SDK: {orisys.__file__}", flush=True)
+    capture = cv2.VideoCapture(str(args.recording.resolve()))
+    frames = []
+    try:
+        for _ in range(12):
+            ok, frame = capture.read()
+            if not ok:
+                raise RuntimeError("recording must contain at least 12 frames")
+            frames.append(frame)
+    finally:
+        capture.release()
+    height, width = frames[0].shape[:2]
+    sources = []
+    for sensor_id in range(1, 5):
+        path = scratch / f"sensor-{sensor_id}.avi"
+        writer = cv2.VideoWriter(str(path), cv2.VideoWriter_fourcc(*"MJPG"), 30, (width, height))
+        try:
+            if not writer.isOpened():
+                raise RuntimeError("cannot create test recording")
+            for frame in frames:
+                writer.write(np.roll(frame, sensor_id, axis=1))
+        finally:
+            writer.release()
+        sources.append(str(path))
+
+    # Keep the SDK implementation intact; redirect only its generated UV cache.
+    open_runtime = partial(FingerRuntime.open, map_cache=str(scratch / "uv-map.npz"))
+    with patch.object(FingerRuntime, "open", side_effect=open_runtime):
+        for count in range(1, 5):
+            bank = FingerSensorBank(sources[:count])
+            try:
+                bank.connect_all()
+                runtimes = list(bank.runtimes.values())
+                for left, right in itertools.combinations(runtimes, 2):
+                    assert left.capture is not right.capture
+                    assert left.tactile.raw_sensor is not right.tactile.raw_sensor
+                    assert not np.shares_memory(left.tactile.flow, right.tactile.flow)
+                for _ in range(3):
+                    readings = bank.read_all()
+                    assert [r.sensor_id for r in readings] == list(range(1, count + 1))
+                    assert all(np.isfinite([r.normal, r.shear_x, r.shear_y]).all() for r in readings)
+                print(f"PASS {count} sources: independent captures/processors, 3 complete rounds", flush=True)
+            finally:
+                bank.close()
+            assert all(runtime.capture is None for runtime in runtimes)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())