四个滤波预设落成机器可读的配置文件，并加上防漂移测试 - What: 新增 examples/filters/filters_{off,low_latency,balanced,low_noise}.json —— 每个都是完整可整块替换的 filters 段（五键齐全：flow_ema_alpha / force_median_window / force_lowpass_cutoff_hz / force_lowpass_order / force_lowpass_sample_rate_hz），数值即 FILTER_PRESETS 展开后的结果；examples/filters/README.md 说明这四份副本的存在与用途；新增 tests/test_filter_presets.py（12 项）：预设名恰为四个、每个示例文件 == 默认块叠加该预设（改预设或改文件都会红）、每份都是含三个开关键的真实 filters 段、三个出厂 bundle（box/mini/finger）的 filters 段仍为全关、且用 external-frame 模式构造真实 Sensor 核对 filters_state() 报的也是全关（文件与设备必须一致）。 - Why: 之前的实现计划里写的是"四个 sensor_<preset>.json 整机配置"，但整机配置要按传感器各复制一份、且必然随 bundle 漂移；README 里内嵌的 JSON 又无法被测试覆盖，等于把"建议用哪档滤波"这句话留在了一处会过时的散文里。改成"filters 片段 + 断言与 FILTER_PRESETS 逐值一致的测试"，既不谎称是完整配置，也不会静默过时。 - Verification: pytest tests/test_filter_presets.py → 12 passed；SDK 全量 335 passed / 15 skipped（唯一失败仍是需要 1200 帧而样例只有 577 帧的 longrun 测试）。 - Not in this change: 未生成按传感器复制的整机配置；docs/filters.md 的预设表未纳入测试（只有这四个文件与代码常量对齐）；app 侧未动。

tests/test_filter_presets.py

@@ -0,0 +1,90 @@
+"""The shipped filter presets and the example configs that document them.
+
+``json.load`` cannot carry comments, so the answer to "which filter should I
+use?" lives in three places that must not drift apart: ``FILTER_PRESETS`` in the
+sensor, the table in ``docs/filters.md``, and the copy-paste files in
+``examples/filters/``. The presets are the source of truth; these tests fail
+when a copy stops matching them.
+"""
+
+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+import pytest
+
+from orisys import Sensor
+from orisys.calibration import filters_fingerprint
+from orisys.sensor import FILTER_PRESETS, available_filter_presets
+from orisys import configs as orisys_configs
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+EXAMPLES = REPO_ROOT / "examples" / "filters"
+BUNDLES = ("box", "mini", "finger")
+
+#: What every shipped bundle says: filtering is opt-in, so a fresh install
+#: records the raw reading and the operator turns a stage on deliberately.
+ALL_OFF = {
+    "flow_ema_alpha": 1.0,
+    "force_median_window": 1,
+    "force_lowpass_cutoff_hz": 0.0,
+    "force_lowpass_order": 2,
+    "force_lowpass_sample_rate_hz": "auto",
+}
+
+
+def test_the_preset_names_are_the_documented_ones():
+    assert sorted(available_filter_presets()) == [
+        "balanced",
+        "low_latency",
+        "low_noise",
+        "off",
+    ]
+    # ``available_filter_presets`` hands out copies: a UI cannot edit the truth.
+    snapshot = available_filter_presets()
+    snapshot["off"]["flow_ema_alpha"] = 0.0
+    assert FILTER_PRESETS["off"]["flow_ema_alpha"] == 1.0
+
+
+@pytest.mark.parametrize("preset", sorted(FILTER_PRESETS))
+def test_every_example_file_still_matches_its_preset(preset: str):
+    path = EXAMPLES / f"filters_{preset}.json"
+    assert path.is_file(), f"missing example for preset {preset!r}: {path}"
+    block = json.loads(path.read_text(encoding="utf-8"))
+    # A whole ``filters`` block: the preset's own keys on top of the defaults
+    # every config needs, and nothing else.
+    expected = dict(ALL_OFF)
+    expected.update(FILTER_PRESETS[preset])
+    assert block == expected, f"{path.name} drifted from preset {preset!r}"
+
+
+def test_every_example_file_is_a_real_filters_block():
+    """A file that cannot be dropped into a config is documentation that lies."""
+    for preset in FILTER_PRESETS:
+        block = json.loads((EXAMPLES / f"filters_{preset}.json").read_text(encoding="utf-8"))
+        assert isinstance(block, dict) and block, preset
+        for key in ("flow_ema_alpha", "force_median_window", "force_lowpass_cutoff_hz"):
+            assert key in block, f"{preset}: {key} missing"
+
+
+@pytest.mark.parametrize("bundle", BUNDLES)
+def test_shipped_bundles_ship_with_filtering_off(bundle: str):
+    """Nothing filters unless it was asked for."""
+    path = orisys_configs.resolve_sensor_config_path(bundle)
+    assert path is not None and path.is_file(), f"missing bundle: {bundle}"
+    cfg = json.loads(path.read_text(encoding="utf-8"))
+    assert cfg.get("filters") == ALL_OFF, f"{bundle} no longer ships with filtering off"
+
+
+@pytest.mark.parametrize("bundle", BUNDLES)
+def test_shipped_bundles_report_all_off(bundle: str):
+    """The file and the running device have to agree about the shipped default."""
+    sensor = Sensor("external", config_name=bundle, verbose=False, backend="cpu")
+    try:
+        fp = filters_fingerprint(sensor.filters_state())
+    finally:
+        sensor.disconnect()
+    assert fp["measurement"] == {"flow_ema_alpha": 1.0}
+    assert fp["readout"]["force_median_window"] == 1
+    assert fp["readout"]["force_lowpass_cutoff_hz"] == 0.0