feat(LamNI): invalidate X-ray-eye/fine alignment on a new rotation centre

Re-running rotation-center calibration after X-ray-eye alignment (or
fine alignment) was already done left the stale fit/correction in
place, silently calibrated around the old center. Record
lamni_center_found_at and cascade-invalidate via the existing
reset_xray_eye_correction()/reset_correction() whenever a new center
is actually applied, in both find_rotation_center() and
find_rotation_center_smear_experimental().

csaxs_bec/bec_ipython_client/plugins/LamNI/x_ray_eye_align.py

@@ -961,6 +961,7 @@ class XrayEyeAlign:
             if answer in ("", "y", "yes"):
                 dev.lsamx.update_user_parameter({"center": float(new_lsamx)})
                 dev.lsamy.update_user_parameter({"center": float(new_lsamy)})
+                self._mark_center_found_and_invalidate_downstream()
                 print(
                     f"[rotation-center][smear] lsamx.user_parameter['center'] = "
                     f"{dev.lsamx.user_parameter.get('center')}, "
@@ -1116,6 +1117,27 @@ class XrayEyeAlign:
             f"interferometer rtx/rty now read ({rtx_after:.2f}, {rty_after:.2f}) um"
         )
 
+    def _mark_center_found_and_invalidate_downstream(self):
+        """Record that the rotation centre was just (re-)established, and
+        invalidate any X-ray-eye/fine-alignment state calibrated around the
+        previous centre.
+
+        Called right after a new lsamx/lsamy centre is actually applied (by
+        both find_rotation_center() and find_rotation_center_smear_experimental()).
+        Reuses the LamNI alignment mixin's own reset methods rather than
+        introducing separate invalidation logic -- see
+        lamni.xrayeye_alignment_start()/tomo_alignment_scan()/tomo_scan(),
+        which gate on lamni_center_found_at / tomo_fit_xray_eye / corr_pos_x
+        respectively.
+        """
+        import datetime
+
+        self.client.set_global_var(
+            "lamni_center_found_at", datetime.datetime.now().isoformat()
+        )
+        self.lamni.reset_xray_eye_correction()
+        self.lamni.reset_correction()
+
     def find_rotation_center(
         self, sample_type: str = "isolated", keep_shutter_open: bool = False, apply: bool = True
     ):
@@ -1271,6 +1293,7 @@ class XrayEyeAlign:
             if answer in ("", "y", "yes"):
                 dev.lsamx.update_user_parameter({"center": float(new_lsamx)})
                 dev.lsamy.update_user_parameter({"center": float(new_lsamy)})
+                self._mark_center_found_and_invalidate_downstream()
                 print(
                     f"[rotation-center] lsamx.user_parameter['center'] = "
                     f"{dev.lsamx.user_parameter.get('center')}, "