Port the SAR3D background gate, CLEAN and object boxes from Multi_depthnorm_clean

- BG_GATE_ENABLE: frame peak over its median background (sar3d_background); the
  GUI scales the frame with bg_gate_gain and its cloud threshold.
- SAR_CLEAN_ENABLE: CLEAN of a one-frame aperture on a 4x10x4 cm search grid over
  the whole scene; objects in their own scale (sar3d_objects).
- SAR_MARK_ENABLE: boxes by class around object groups (sar3d_marks), with the
  legend under the views.
- SAR_VOXEL_M as three steps X/Y/Z with the notebook defaults 0.025/0.02/0.02.
- GPU backend: image/download/load/project API, per-plane block reduction for the
  maximum, depth gate without FMA; sar3d host code built with -ffp-contract=off.
- References regenerated from notebook cells 1 and 5, with new CLEAN scenes and a
  synthetic box-rule case; docs updated.

data_acq_and_processing/processing/data_processor/include/processing_live_config.hpp

@@ -60,12 +60,14 @@ struct ProcessingLiveConfig {
     float gpr_visible_z_min_m = 0.0F;
     float gpr_visible_z_max_m = 14.0F;
     // 3D SAR (sar3d processor) parameters, named after the reference notebook
-    // Multi_antenna_demonstrate_depthnorm.ipynb (SAR_FRAME_RADIUS, BP_GROUND_DEPTH_M, ...).
+    // Multi_depthnorm_clean.ipynb (SAR_FRAME_RADIUS, BP_GROUND_DEPTH_M, ...).
     // The band, depth gate, antenna selection, speed and look angle are the
     // shared gpr_* fields above.
     std::uint32_t sar3d_frame_radius = 0U;
-    // Edge of the cubic voxel: the notebook's SAR_VOXEL_M with one value for X, Y, Z.
-    float sar3d_voxel_m = 0.02F;
+    // SAR_VOXEL_M: the voxel steps along X, Y and Z.
+    float sar3d_voxel_x_m = 0.025F;
+    float sar3d_voxel_y_m = 0.02F;
+    float sar3d_voxel_z_m = 0.02F;
     float sar3d_bp_ground_depth_m = 1.25F;
     float sar3d_comp_range_power = 0.3F;
     bool sar3d_use_compensation = true;
@@ -74,6 +76,8 @@ struct ProcessingLiveConfig {
     float sar3d_y_min_m = -0.5F;
     float sar3d_y_max_m = 2.0F;
     float sar3d_z_size_m = 0.0F;
+    bool sar3d_bg_gate_enabled = true;   // BG_GATE_ENABLE: peak-to-background ratio for the display
+    bool sar3d_clean_enabled = true;     // SAR_CLEAN_ENABLE: CLEAN of a one-frame aperture into objects
     // When true, the data_processor ignores socket-supplied `vlc` updates and
     // keeps using `gpr_speed_m_s` from this file. Mirrored from the GUI's
     // "ignore socket speed" checkbox.

data_acq_and_processing/processing/data_processor/src/processing_live_config.cpp

@@ -231,7 +231,9 @@ auto parse_geometry(const Json& value, const char* position_field, std::uint32_t
         config.sar3d_frame_radius = parse_u32_number(*found, "processing.sar3d_frame_radius");
     }
     for (const auto& [key, target] : {
-             std::pair{"sar3d_voxel_m", &config.sar3d_voxel_m},
+             std::pair{"sar3d_voxel_x_m", &config.sar3d_voxel_x_m},
+             std::pair{"sar3d_voxel_y_m", &config.sar3d_voxel_y_m},
+             std::pair{"sar3d_voxel_z_m", &config.sar3d_voxel_z_m},
              std::pair{"sar3d_bp_ground_depth_m", &config.sar3d_bp_ground_depth_m},
              std::pair{"sar3d_comp_range_power", &config.sar3d_comp_range_power},
              std::pair{"sar3d_x_size_m", &config.sar3d_x_size_m},
@@ -244,6 +246,8 @@ auto parse_geometry(const Json& value, const char* position_field, std::uint32_t
     for (const auto& [key, target] : {
              std::pair{"sar3d_use_compensation", &config.sar3d_use_compensation},
              std::pair{"sar3d_normalize_each_frame", &config.sar3d_normalize_each_frame},
+             std::pair{"sar3d_bg_gate_enabled", &config.sar3d_bg_gate_enabled},
+             std::pair{"sar3d_clean_enabled", &config.sar3d_clean_enabled},
          }) {
         assign_optional(root, key, *target);
     }