feat(editor): add --gen-texture-dewdrops scattered-droplets

75th procedural texture: N small water droplets at hash-
derived (cx, cy, R) positions blended onto bg via radial
brightness — bright at the drop center fading to bg at its
edge. Where drops overlap they accumulate brighter
(max-of-individual-contributions, not additive — so the
result stays inside the [bg, drop] color range).

Each drop gets a hash-derived radius in the [maxR/4, maxR]
range so the surface has a natural mix of small and large
droplets. Two-pass (compute brightness map, then write
pixels) so overlap accumulation works correctly.

Useful for morning-grass blades, wet-glass overlays, leaf
surfaces after rain, magic-pool fizz, snake-fountain
splash zones, dragon-breath-aftermath ground.

tools/editor/cli_help.cpp

@@ -183,6 +183,8 @@ void printUsage(const char* argv0) {
     std::printf("                         Embroidery: grid of cross-stitch X marks (counted-thread textile / sampler / folk-art trim)\n");
     std::printf("  --gen-texture-lightbeam <out.png> <bgHex> <beamHex> [beamHalfW] [vFadeFrac] [u|d] [W H]\n");
     std::printf("                         Lightbeam: vertical sun-ray gradient fading horizontally + vertically (sunbeam / holy radiance)\n");
+    std::printf("  --gen-texture-dewdrops <out.png> <bgHex> <dropHex> [dropCount] [maxR] [seed] [W H]\n");
+    std::printf("                         Dewdrops: scattered translucent water drops with radial brightness (grass / glass / leaf surfaces)\n");
     std::printf("  --add-texture-to-zone <zoneDir> <png-path> [renameTo]\n");
     std::printf("                         Copy an existing PNG into <zoneDir> (optionally renaming it on the way in)\n");
     std::printf("  --gen-mesh <wom-base> <cube|plane|sphere|cylinder|torus|cone|ramp> [size]\n");