feat(bringup): floor surface type classifier on D435i RGB (Issue #249)
Adds multi-feature nearest-centroid classifier for 6 surface types:
carpet, tile, wood, concrete, grass, gravel. Features: circular hue mean,
saturation mean/std, brightness, Laplacian texture variance, Sobel edge
density — all extracted from the bottom 40% of each frame (floor ROI).
Majority-vote temporal smoother (window=5) suppresses single-frame noise.
Publishes std_msgs/String on /saltybot/floor_type at 2 Hz.
34/34 pure-Python tests pass (no ROS2 required).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
sl-perception
32857435a1