feat(editor): add --gen-mesh-standing-torch hall-lining torch

83rd procedural mesh primitive. Tall standing floor torch:

  • post — thin Y-axis cylinder rising from the floor
  • bowl — wider shallow Y-axis cylinder (the fire bowl)
    sitting on top of the post

Distinct from --gen-mesh-brazier (squat fire-bowl on a
short stem with a wide-base silhouette) — standing-torch
is the tall thin walking-height variant for lining
hallways, ceremonial paths, dungeon entries, palace
entrance walks, watch-station lighting.

Validates that postR < bowlR so the silhouette always
reads as the wider-bowl-on-thinner-pole shape.

Watertight under weld (verified 168 manifold edges, 0
boundary, 0 non-manifold). Two clean addClosedCylinderY
calls — pattern is now well-established for cylindrical
prop primitives.

tools/editor/cli_arg_required.cpp

@@ -62,6 +62,7 @@ const char* const kArgRequired[] = {
     "--gen-mesh-statue-base", "--gen-mesh-bird-bath",
     "--gen-mesh-planter-box", "--gen-mesh-urn", "--gen-mesh-candle",
     "--gen-mesh-lantern", "--gen-mesh-chalice",
+    "--gen-mesh-standing-torch",
     "--gen-camp-pack", "--gen-blacksmith-pack", "--gen-village-pack",
     "--gen-temple-pack", "--gen-graveyard-pack",
     "--gen-garden-pack", "--gen-dock-pack", "--gen-tavern-pack",