fix(lamni): allow entering 0 to disable circular FOV in Tomo Params GUI

The scan already treats fov_circular==0 as "disabled" and defaults to
it, but the GUI spinbox floor of 0.1 made 0 unreachable. Lower the
floor to 0.0 and label the field so the meaning is explicit.

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

csaxs_bec/bec_widgets/widgets/tomo_params/tomo_params.py

@@ -2286,7 +2286,7 @@ SETUP_PROFILES: dict[str, dict[str, Any]] = {
         "has_180_mode": False,
         "has_single_point": False,
         "has_zero_deg_reference": True,
-        "fov_fields": [("tomo_circfov", "Circular FOV (µm)", 0.1, 200.0, 2)],
+        "fov_fields": [("tomo_circfov", "Circular FOV (µm, 0 = disabled)", 0.0, 200.0, 2)],
         "stitch_fields": [
             ("lamni_stitch_x", "Stitch x", 0, 50),
             ("lamni_stitch_y", "Stitch y", 0, 50),