feat(LamNI): add automated rotation-center calibration via X-ray eye

lsamx_center/lsamy_center have to be re-measured by hand for nearly every
new sample (the rotation stage is tilted on top of lsamx/lsamy, so the
effective axis position shifts with sample thickness/mounting). Add
XrayEyeAlign.find_rotation_center()/lamni.rotation_center_calibration_start()
to automate this using the existing X-ray eye GUI and lamni_move_to_scan_center
interferometer-feedback move:

- "isolated" sample: click particle centre at 0 and 180 deg, use the
  midpoint (angle-tilt-independent) as the rotation axis position.
- "extended" sample: live 0->180->0 sweep for visual identification, single
  click, then a verification sweep and an accept/iterate prompt.

Both write the result to lsamx/lsamy's "center" userParameter after
confirmation. Heavily verbose logging throughout since this is fundamentally
an interactive, hardware-in-the-loop procedure that can't be fully exercised
by automated tests.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/user/ptychography/lamni.md

@@ -18,7 +18,26 @@ Mount the new sample. The X-ray eye is already in, but the X-ray optics needs to
 
 #### Coarse axis alignment
 
-The effective position of the axis of rotation shifts with sample thickness or mounting position of the sample along the axis of rotation. The position of the axis of rotation is controlled by user parameters **center** of the **lsamx** and **lsamy** stages. To observe the axis of rotation obtain the position of the Fresnel zone plate on the X-ray eye, possibly in the *ueye gui* by:
+The effective position of the axis of rotation shifts with sample thickness or mounting position of the sample along the axis of rotation. The position of the axis of rotation is controlled by user parameters **center** of the **lsamx** and **lsamy** stages.
+
+The recommended way to (re-)measure `center` for a new sample is the GUI-driven procedure below. It replaces the fully manual jog-by-hand steps that used to live here; those are kept further down as a fallback for when the automated procedure or the GUI is unavailable.
+
+**Automated rotation-center calibration**
+
+`lamni.rotation_center_calibration_start(sample_type="isolated")`
+
+This opens the X-ray eye widget and walks through the calibration interactively. Choose `sample_type` based on what's mounted:
+
+- `"isolated"` — for a sparse/isolated particle. You submit its centre position once at 0° and once at 180°; the midpoint of the two is the rotation axis' projected position (this works regardless of the axis tilt). No further confirmation step.
+- `"extended"` — for a non-isolated/textured sample where the rotation centre can be identified visually. The sample sweeps 0° → 180° → 0° with the live view left open so you can watch for the point that doesn't move, then you submit a single click at 0°. The correction is applied, a short verification sweep (0° → 45° → 0°) runs, and you're asked *"Are you happy with this alignment, or shall we do another iteration?"* — answer `n` to refine further.
+
+At the end you're shown the computed `lsamx_center`/`lsamy_center` and asked to confirm before they're written via `dev.lsamx.update_user_parameter(...)` / `dev.lsamy.update_user_parameter(...)`.
+
+Pass `keep_shutter_open=True` if it's hard to relocate the sample between steps, matching `xrayeye_alignment_start()` below. Interrupt with Ctrl-C to abort; the crosshair and DAP forwarding are cleaned up automatically.
+
+**Manual fallback**
+
+To observe the axis of rotation obtain the position of the Fresnel zone plate on the X-ray eye, possibly in the *ueye gui* by:
 
 1. `lamni.lfzp_in()`, move the FZP in
 2. `dev.rtx.controller.feedback_disable()`, disable feedback to allow lsam movements