NavMap maps manager: local NavMap around the robot

[fmrico]

Fixes #119

With <plugin>.local.enabled, the NavMap maps manager keeps a NavMap around the robot, in its frame, rebuilt continuously from the point perceptions in NavState. Each rebuild:

1. accumulates the scans in odom over local.accumulate_time (a single 3D scan is sparse rings);
2. crops them to the window (local.range, local.min_z/max_z) in local.frame and voxelizes them;
3. meshes them with navmap_ros::from_points (local.resolution, max_dz, max_slope_deg, min_clearance, min_surface_area, max_hole_area);
4. publishes the NavMap on <plugin>/map and puts it in NavState, where the filters run on it as usual.

Grabacion.de.pantalla.desde.2026-10-15.12-59-24.mp4

The parameters are documented in the package README.

Fixes found on the way

• A new map now replaces the one in NavState. Before, only the first map ever got there: a map received later on incoming_occ_map / incoming_pc2_map was published but never used.
• The ObstacleFilter works in the NavMap's own frame, not always in map.
• The InflationFilter skips an empty NavMap instead of logging an error.

Validation

Summit XL in the URJC excavation (launch in EasyNavigation/easynav_playgrounds, separate PR), headless, driving 15 s with /cmd_vel:

• Maps: the first one after 8 s, then one every 0.5 s (local.freq: 2), always in base_footprint, following the robot.
• Coverage: 67–181 m² of the 16 × 16 m window. The rest is the lidar's blind zone near the robot, occlusions and slopes over the mesher's limit.
• Log: no errors.

Tests

• New (navmap_local_mode_tests):
  • the NavMap is built in the robot frame, cropped to the window, with the ground at its height;
  • it follows the robot and replaces the map in NavState;
  • the mode is disabled by default;
  • nothing breaks without an odom → robot transform.
• The whole package suite passes, linters included: 119 tests.