新增统一力读数会话 ForceSession

把同帧测量、空载归零、模型推断与共用后处理收进一个 SDK 会话，Studio 显示与记录使用同一样本；旧 Sensor 读数接口保持兼容。以 force session 与受影响 SDK 套件、lint 与文档门禁验证，硬件与真实载荷精度未验证。

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CpCfJF6SvonMKmPZhzKZHb

src/orisys/finger/runtime.py

@@ -454,6 +454,60 @@ class FingerRuntime:
         self.tactile.push_frame(unrolled, already_gray=True)
         return unrolled
 
+    # ------------------------------------------- session measurement seam
+    def enable_measurement_session(self) -> None:
+        """Hand force readout to a ``ForceSession`` (the explicit new entry)."""
+        self.tactile.raw_sensor.enable_measurement_session()
+
+    def disable_measurement_session(self) -> None:
+        """Return to the historical automatic model/readout path."""
+        self.tactile.raw_sensor.disable_measurement_session()
+
+    def reset_tracker(self) -> None:
+        """Reset the tactile tracker at a frame boundary (session zeroing half)."""
+        self.tactile.raw_sensor.reset_tracker()
+
+    def read_measurement_frame(
+        self,
+        source_frame,
+        *,
+        frame_id: int,
+        timestamp_s: float | None = None,
+        want_field: bool = False,
+        want_contact: bool = False,
+    ):
+        """Unroll one source frame and measure it once, without calibration."""
+        del timestamp_s  # signal time is carried by the caller's FrameStamp
+        self.process_frame(source_frame)
+        return self.tactile.raw_sensor.measure_current_frame(
+            frame_id=frame_id,
+            want_field=want_field,
+            want_contact=want_contact,
+        )
+
+    def current_measurement(
+        self, *, want_field: bool = False, want_contact: bool = False
+    ):
+        """Same-frame measurement features already produced by the pipeline (no recompute).
+
+        Additive: forwards to the tactile sensor's session seam so a pipeline
+        consumer can hand the frame to ``ForceSession`` without a second
+        unroll/flow/HHD pass.
+        """
+        return self.tactile.raw_sensor.current_measurement(
+            want_field=want_field, want_contact=want_contact
+        )
+
+    @property
+    def calibration_context(self):
+        """The pipeline context the open model was validated against, if any."""
+        return self.tactile.raw_sensor.calibration_context
+
+    @property
+    def calibration(self):
+        """The force calibration the open runtime holds (additive read-only accessor)."""
+        return getattr(self.tactile.raw_sensor, "calibration", None)
+
     def grab_and_process(self, *, color=False):
         ok, frame = self.read_source()
         if not ok: