采集端统一由 SDK 滤波、显示端不再二次滤波，session.json 记录生效值 - What: sdk_worker/finger_worker 删除硬编码的 sensor.configure(lowpass_cutoff_hz=LOWPASS_CUTOFF_HZ, lowpass_sample_rate_hz=...) —— 它会让界面上的曲线与 CSV 走两条不同的滤波路径；改为在会话打开设备后调用 FilterSettings.apply_to(sensor)，并把两件事分别记下来：self._filter_state = effective_filters(sensor)（设备报的**实际**生效值，供界面与记录使用）与 self._filters_unsupported（该 SDK 应用不了的键，老 SDK 必须被看见而不是被吞掉）；新增 worker 的 set_filter_settings()/filter_settings()/filter_state()/filters_unsupported() 访问器，start() 时清空上一会话的 filter_state（与 _calibration_version 同样的理由：新会话不能继承旧会话的说法）。finger_worker 保留原有的"runtime 可能拒绝 configure"的容错，但改成记日志并把全部键标为未应用。app_window 新增 _filter_settings()（从 preferences 的 plot_* 键读，空/坏值即"什么都不滤"）与 _filter_metadata()（向**正在跑的** worker 要设备实际状态，写成 session.json 的 filters 块：measurement/readout/describe/source，SDK 缺键时附 unsupported_by_sdk）；_start_session 在 start() 之前把设置交给 worker。ui/force_plots.py 把 MetricHistory 的 lowpass_cutoff_hz 从 LOWPASS_CUTOFF_HZ 改成 0.0：SDK 已经滤过一遍，且这个 buffer 就是进记录的那个，显示端再滤会让曲线画出 CSV 里根本没有的数据（原来用的还是零相位 filtfilt，非因果）。acquisition/constants.py 删掉 LOWPASS_CUTOFF_HZ（"app 在 10 Hz 滤波"这件事不存在了），FORCE_SAMPLE_RATE_HZ 保留。tests/test_force_filters.py 增 3 项：worker 未开设备时 filter_state() 为 {}（"没问过"不等于"没在滤"）、effective_filters() 对没有 filters_state() 的 SDK 返回 {}、以及对着真实 SDK 的端到端断言（external-frame 构造 box Sensor → apply_to → filters_state 回报 flowEMA(0.5)+median(3)+lowpass(10Hz,order2) → force_triplets 两个 buffer 都在 → 全关也可表达）。apps/studio/tools/ui_check.py 的 _StuckWorker 补上新合约方法（set_filter_settings/filter_settings/filter_state/filters_unsupported），否则窗口一启动就 AttributeError。 - Why: 用户的核心要求是"显示的和记录的必须一致，包括所有滤波"，并决定整条链留在 SDK、app 只通过 Sensor.configure 驱动。此前 app 硬编码 10 Hz 低通（SDK 侧）**加上**显示端 filtfilt（app 侧），同一次采集的两份数据经过两条不同的滤波路径；session.json 里的 filter 块也只是照抄常量，说的不是设备在做的事。 - Verification: shared 全量 156 passed（含新增的真实 SDK 端到端断言）；studio 85 项测试通过（修好 _StuckWorker 合约后）；ui_check 554 项检查、4 个场景 0 失败；编译通过。 - Not in this change: 曲线表头的齿轮按钮与滤波设置对话框（因此现在还只能改 preferences.json 的 plot_* 键来换滤波）、CSV 的 17 列与未滤波第二 buffer、回放界面显示滤波前曲线、发布说明里"默认不再滤波"的措辞。

shared/tests/test_force_filters.py

@@ -246,6 +246,68 @@ def test_settings_round_trip_through_a_preferences_mapping():
     assert settings_from_mapping(None).active() is False
 
 
+# ------------------------------------------------- the worker's filter contract
+def test_a_worker_reports_no_filter_state_until_a_session_has_one():
+    """``{}`` means "not asked yet", which is not the same as "nothing filters"."""
+    from orisys_app_shared.acquisition.sdk_worker import SdkAcquisitionWorker
+
+    worker = SdkAcquisitionWorker()
+    assert worker.filter_state() == {}
+    assert worker.filters_unsupported() == ()
+    worker.set_filter_settings(FilterSettings(median_window=3))
+    assert worker.filter_settings().median_window == 3
+    # Clearing the preference is "nothing filters", not "keep the last choice".
+    worker.set_filter_settings(None)
+    assert worker.filter_settings() == FilterSettings()
+    assert worker.filter_settings().active() is False
+
+
+def test_effective_filters_says_nothing_when_the_sdk_cannot_answer():
+    from orisys_app_shared.force.filters import effective_filters
+
+    assert effective_filters(object()) == {}
+
+    class Broken:
+        def filters_state(self):
+            raise RuntimeError("no")
+
+    assert effective_filters(Broken()) == {}
+
+
+def test_the_settings_reach_a_real_sensor_and_come_back_as_the_truth():
+    """The whole point of this module, against the SDK itself.
+
+    No hardware: the SDK's external-frame mode constructs a Sensor from its own
+    bundle, which is exactly what the acquisition worker does before applying
+    the session's filters.
+    """
+    orisys = pytest.importorskip("orisys")
+    from orisys_app_shared.force.filters import effective_filters
+
+    sensor = orisys.Sensor("external", config_name="box", verbose=False)
+    try:
+        assert sensor.filters_state()["any_stage_applied"] is False
+        unsupported = FilterSettings(
+            flow_ema_alpha=0.5, median_window=3, lowpass_hz=10.0
+        ).apply_to(sensor)
+        assert unsupported == (), "the installed SDK is missing filter settings"
+        state = effective_filters(sensor)
+        assert state["measurement"]["flow_ema_alpha"] == 0.5
+        assert state["readout"]["force_median_window"] == 3
+        assert state["readout"]["force_lowpass_applied"] is True
+        read_back = FilterSettings.from_filters_state(state)
+        assert read_back.describe() == "flowEMA(0.5) + median(3) + lowpass(10Hz,order2)"
+        # ...and the unfiltered pair is available for the second buffer.
+        triplets = sensor.force_triplets()
+        assert set(triplets) == {"filtered", "unfiltered"}
+        assert set(triplets["unfiltered"]) == {"raw", "newton"}
+        # Turning everything off is expressible, and the device agrees.
+        FilterSettings().apply_to(sensor)
+        assert effective_filters(sensor)["any_stage_applied"] is False
+    finally:
+        sensor.disconnect()
+
+
 # ------------------------------------------- the reference chain (SDK parity)
 def test_a_disabled_chain_is_a_pass_through():
     chain = ForceFilterChain(FilterSettings())