KISS-Matcher: 3 presets + brighter initial-match color

Presets switchable from a sidebar list (loaded from a tiny index JSON):

  - vel16 (Velodyne VLP-16, indoor)        — 1.7 MB committed
  - vel64 (Velodyne HDL-64, KITTI s2s)     — 2.9 MB committed
  - kitti0007 (KITTI seq 00 ↔ 07 submaps)  — 6.4 MB committed (1 m
        voxel-downsampled from upstream's 27 MB raw to keep the repo
        slim; algorithm result is unchanged at the demo's voxel size)

INITIAL_COLOR slate-600 (#475569) → slate-300 (#cbd5e1). The previous
slate sat too close to the bg on phones / dim displays — they now read
clearly against it while staying visibly muted relative to the amber
final inliers.

tools/gen_kiss_matcher_data.py iterates a PRESETS list now, writes one
JSON per preset plus a kiss_matcher_index.json the page reads first to
populate the switcher buttons. Old single-file kiss_matcher.json is
removed.

tools/_voxel_downsample_pcd.py is a one-shot helper used during
dataset onboarding (lives in tools/ for reproducibility, not part of
the chapter pipeline).

KissMatcher.tsx loads the index once, defaults to vel64, swaps src /
tgt / matches when the user clicks a preset; resets pose offset and
camera framing on switch.

Author: LimHyungTae

materials/kiss_kitti0007_src.pcd

@@ -0,0 +1,40 @@
+{
+  "presets": [
+    {
+      "id": "vel16",
+      "label": "Velodyne VLP-16 (indoor)",
+      "url": "data/precomputed/kiss_matcher_vel16.json",
+      "stats": {
+        "numSrcPoints": 25370,
+        "numTgtPoints": 25049,
+        "numInitialMatches": 544,
+        "numFinalInliers": 112,
+        "numRotationInliers": 55
+      }
+    },
+    {
+      "id": "vel64",
+      "label": "Velodyne HDL-64 (KITTI scan-to-scan)",
+      "url": "data/precomputed/kiss_matcher_vel64.json",
+      "stats": {
+        "numSrcPoints": 122303,
+        "numTgtPoints": 127032,
+        "numInitialMatches": 409,
+        "numFinalInliers": 26,
+        "numRotationInliers": 19
+      }
+    },
+    {
+      "id": "kitti0007",
+      "label": "KITTI seq 00 \u2194 seq 07 (cross-trajectory submaps)",
+      "url": "data/precomputed/kiss_matcher_kitti0007.json",
+      "stats": {
+        "numSrcPoints": 456163,
+        "numTgtPoints": 103821,
+        "numInitialMatches": 4986,
+        "numFinalInliers": 36,
+        "numRotationInliers": 20
+      }
+    }
+  ]
+}