feat(editor): add --gen-texture-lattice diagonal-grid pattern

41st procedural texture: garden trellis / mesh fence done as
two perpendicular sets of diagonal lines (+45° and -45°)
drawn simultaneously across the whole image so they form
diamond-shaped openings between the lines.

Distinct from --gen-texture-herringbone (which alternates
strip orientation): lattice draws both diagonal sets at every
pixel. Useful for trellises, wire mesh fences, dragon-scale
chain mail, decorative window grilles. Defaults to 24-px line
spacing with 3-px line width.

tools/editor/cli_gen_texture.cpp

@@ -3887,6 +3887,80 @@ int handleGingham(int& i, int argc, char** argv) {
     return 0;
 }
 
+int handleLattice(int& i, int argc, char** argv) {
+    // Lattice: garden trellis — two sets of diagonal lines, one
+    // at +45° and one at -45°, drawn simultaneously across the
+    // whole image so they form diamond-shaped openings between
+    // the lines. Distinct from --gen-texture-herringbone (which
+    // alternates strip orientation) — this draws both diagonals
+    // at every pixel.
+    std::string outPath  = argv[++i];
+    std::string bgHex    = argv[++i];
+    std::string lineHex  = argv[++i];
+    int lineSpacing = 24;
+    int lineWidth   = 3;
+    int W = 256, H = 256;
+    if (i + 1 < argc && argv[i + 1][0] != '-') {
+        try { lineSpacing = std::stoi(argv[++i]); } catch (...) {}
+    }
+    if (i + 1 < argc && argv[i + 1][0] != '-') {
+        try { lineWidth = std::stoi(argv[++i]); } catch (...) {}
+    }
+    if (i + 1 < argc && argv[i + 1][0] != '-') {
+        try { W = std::stoi(argv[++i]); } catch (...) {}
+    }
+    if (i + 1 < argc && argv[i + 1][0] != '-') {
+        try { H = std::stoi(argv[++i]); } catch (...) {}
+    }
+    if (W < 1 || H < 1 || W > 8192 || H > 8192 ||
+        lineSpacing < 4 || lineSpacing > 256 ||
+        lineWidth < 1 || lineWidth >= lineSpacing) {
+        std::fprintf(stderr,
+            "gen-texture-lattice: invalid dims (W/H 1..8192, spacing 4..256, width 1..spacing-1)\n");
+        return 1;
+    }
+    uint8_t br_, bg_, bb_, lr, lg, lb_;
+    if (!parseHex(bgHex, br_, bg_, bb_) ||
+        !parseHex(lineHex, lr, lg, lb_)) {
+        std::fprintf(stderr,
+            "gen-texture-lattice: bg or line hex color is invalid\n");
+        return 1;
+    }
+    std::vector<uint8_t> pixels(static_cast<size_t>(W) * H * 3, 0);
+    for (int y = 0; y < H; ++y) {
+        for (int x = 0; x < W; ++x) {
+            // +45° line set: where (x + y) mod spacing is small.
+            int posMod = ((x + y) % lineSpacing + lineSpacing) % lineSpacing;
+            // -45° line set: where (x - y) mod spacing is small.
+            int negMod = ((x - y) % lineSpacing + lineSpacing) % lineSpacing;
+            bool onLine = (posMod < lineWidth) || (negMod < lineWidth);
+            uint8_t r, g, b;
+            if (onLine) {
+                r = lr; g = lg; b = lb_;
+            } else {
+                r = br_; g = bg_; b = bb_;
+            }
+            size_t idx = (static_cast<size_t>(y) * W + x) * 3;
+            pixels[idx + 0] = r;
+            pixels[idx + 1] = g;
+            pixels[idx + 2] = b;
+        }
+    }
+    if (!stbi_write_png(outPath.c_str(), W, H, 3,
+                        pixels.data(), W * 3)) {
+        std::fprintf(stderr,
+            "gen-texture-lattice: stbi_write_png failed for %s\n",
+            outPath.c_str());
+        return 1;
+    }
+    std::printf("Wrote %s\n", outPath.c_str());
+    std::printf("  size       : %dx%d\n", W, H);
+    std::printf("  bg / line  : %s / %s\n", bgHex.c_str(), lineHex.c_str());
+    std::printf("  diagonals  : ±45° at %d-px spacing, %d-px width\n",
+                lineSpacing, lineWidth);
+    return 0;
+}
+
 }  // namespace
 
 bool handleGenTexture(int& i, int argc, char** argv, int& outRc) {
@@ -4012,6 +4086,9 @@ bool handleGenTexture(int& i, int argc, char** argv, int& outRc) {
     if (std::strcmp(argv[i], "--gen-texture-gingham") == 0 && i + 4 < argc) {
         outRc = handleGingham(i, argc, argv); return true;
     }
+    if (std::strcmp(argv[i], "--gen-texture-lattice") == 0 && i + 3 < argc) {
+        outRc = handleLattice(i, argc, argv); return true;
+    }
     return false;
 }
 

tools/editor/cli_help.cpp

@@ -115,6 +115,8 @@ void printUsage(const char* argv0) {
     std::printf("                         Spider web: N radial spokes + M concentric polygonal rings centered on the image\n");
     std::printf("  --gen-texture-gingham <out.png> <bgHex> <stripeHex> <crossHex> [spacing] [width] [W H]\n");
     std::printf("                         Gingham: 3-tone fabric — bg + perpendicular stripes + darker color where they cross\n");
+    std::printf("  --gen-texture-lattice <out.png> <bgHex> <lineHex> [spacing] [width] [W H]\n");
+    std::printf("                         Lattice: ±45° diagonal grid forming diamond openings (garden trellis / mesh fence)\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");

tools/editor/main.cpp

@@ -171,6 +171,7 @@ int main(int argc, char* argv[]) {
         "--gen-texture-shingles", "--gen-texture-frost",
         "--gen-texture-parquet", "--gen-texture-bubbles",
         "--gen-texture-spider-web", "--gen-texture-gingham",
+        "--gen-texture-lattice",
         "--validate-glb", "--info-glb", "--info-glb-tree", "--info-glb-bytes",
         "--validate-jsondbc", "--check-glb-bounds", "--validate-stl",
         "--validate-png", "--validate-blp",