Hidden Realities — Milkweed & shared wind field

First plate of the hidden-realities series: natural subjects as
instrument photographs. One invisible wind field, three detectors —
dunes (time-integrated, what the sand remembers), water (instantaneous),
milkweed seeds (advected test particles).

- src/field/wind.js: divergence-free curl-noise field with closed-form
  time integral; displacement / scalar / stepped-vec samplers.
- src/scene/umbel.js: milkweed head as a particle interaction vertex;
  burst releases pedicels to seed. src/scene/drift.js: seeds advected,
  same track contract as track.js.
- composition.js: switch -> GROUP_BUILDERS registry; fieldLake/flora/
  drift layers + wind plumbing. carpet.js/perspgrid.js: warpFn/phaseFn/
  modesFn/heightFn injection hooks (default off, no regression).
- schema + composer panels, dunelake ink palette, dune-lake template,
  tools/dunelake.mjs (17-plate matrix) and its curated SVG set.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

output/dunelake/palette_dusk.mjs

@@ -0,0 +1,240 @@
+/* dune-lake-milkweed · dusk — sand holds the late light, slate water */
+export const composition = {
+  "size": 1600,
+  "seed": "CRITICALDUNE-7",
+  "wind": {
+    "seed": "ZEPHYR-011",
+    "strength": 0.8,
+    "scale": 1.6,
+    "gust": 0.4,
+    "time": 1.4
+  },
+  "background": {
+    "color": "rgb(210,190,170)",
+    "film": {
+      "opacity": 0.5,
+      "density": 0.5,
+      "seed": 8
+    },
+    "aging": {
+      "opacity": 0.35,
+      "scratches": 3,
+      "dust": 0.45,
+      "foxing": 0.5,
+      "seed": 5
+    },
+    "grain": {
+      "opacity": 0.38,
+      "intensity": 0.42,
+      "seed": 19
+    },
+    "glow": {
+      "strength": 0.5,
+      "followSun": false
+    },
+    "vignette": {
+      "strength": 0.32,
+      "mode": "radial",
+      "cx": 0.5,
+      "cy": 0.42,
+      "radius": 0.9,
+      "angle": 90,
+      "start": 0.5
+    }
+  },
+  "fieldLake": {
+    "enabled": true,
+    "layerOpacity": 1,
+    "transform": {
+      "x": 0,
+      "y": 0,
+      "rotation": 0,
+      "scale": 1
+    },
+    "seed": "LIMNOS-CRITICALDUNE-7",
+    "color": {
+      "hueBack": 0.62,
+      "hueFront": 0.58,
+      "sat": 0.5,
+      "light": 0.42
+    },
+    "layers": 2,
+    "chaos": 0.1,
+    "blips": 0.2,
+    "mound": 0,
+    "horizonY": 0.39,
+    "lines": 24,
+    "wind": {
+      "warp": 0.55
+    },
+    "clip": [
+      0,
+      0.35000000000000003,
+      1,
+      0.5700000000000001
+    ]
+  },
+  "fieldSea": {
+    "enabled": true,
+    "layerOpacity": 1,
+    "transform": {
+      "x": 0,
+      "y": 0,
+      "rotation": 0,
+      "scale": 1
+    },
+    "seed": "AEOLIAN-CRITICALDUNE-7",
+    "color": {
+      "hueBack": 0.05,
+      "hueFront": 0.95,
+      "sat": 0.5,
+      "light": 0.4
+    },
+    "layers": 3,
+    "chaos": 0.22,
+    "blips": 0.35,
+    "mound": 0.55,
+    "horizonY": 0.55,
+    "lines": 52,
+    "wind": {
+      "warp": 0.9
+    }
+  },
+  "fieldGrid": {
+    "enabled": false,
+    "layerOpacity": 1,
+    "pos": "over",
+    "style": "floor",
+    "transform": {
+      "x": 0,
+      "y": 0,
+      "rotation": 0,
+      "scale": 1
+    },
+    "color": {
+      "hue": 0.5,
+      "hue2": 0.55,
+      "sat": 0.32,
+      "lightNear": 0.34,
+      "lightFar": 0.62
+    },
+    "opacity": 0.44,
+    "pitch": 0.45,
+    "yaw": 0.42,
+    "persp": 1.1,
+    "dist": 2.8,
+    "nx": 16,
+    "nz": 24,
+    "originY": 0.34,
+    "ripple": {
+      "amp": 0,
+      "freqI": 0.5,
+      "freqK": 0.35,
+      "phase": 0
+    },
+    "resonance": {
+      "amp": 0,
+      "q": 14,
+      "axis": "ties",
+      "hue": 0.06,
+      "sat": 0.7,
+      "light": 0.45
+    },
+    "wind": {
+      "ripple": 0
+    }
+  },
+  "disk": {
+    "enabled": false,
+    "layerOpacity": 1,
+    "transform": {
+      "x": 0,
+      "y": -0.26,
+      "rotation": 0,
+      "scale": 0.78
+    },
+    "hue": 0.06,
+    "sat": 0.82,
+    "size": 0.16,
+    "pressure": 0.85,
+    "intensity": 0.85,
+    "striations": 0.6,
+    "stain": 0.35,
+    "soften": 1.35
+  },
+  "bubble": {
+    "enabled": false,
+    "layerOpacity": 1,
+    "transform": {
+      "x": 0.28,
+      "y": -0.1,
+      "rotation": 10,
+      "scale": 0.78
+    },
+    "palette": "magentarise",
+    "saturation": 1.05,
+    "traceHue": 0,
+    "transparentBase": true,
+    "primaries": 18,
+    "sweepers": 5,
+    "cosmics": 6,
+    "eloss": 0.34,
+    "bfield": 1,
+    "deltaRate": 0.6,
+    "showBoundary": true,
+    "boundaryR": 0.45,
+    "boundaryY": 0.35,
+    "boundaryOpacity": 0.4,
+    "instrument": 0.35
+  },
+  "flora": {
+    "enabled": true,
+    "layerOpacity": 1,
+    "transform": {
+      "x": -0.34,
+      "y": 0.42,
+      "rotation": 0,
+      "scale": 1
+    },
+    "palette": "dunelake",
+    "saturation": 1.05,
+    "count": 3,
+    "scale": 0.42,
+    "pedicels": 46,
+    "droop": 0.4,
+    "spread": 1,
+    "burst": 0.25,
+    "floretSize": 1,
+    "clusterW": 0.7,
+    "clusterH": 0.3,
+    "seed": "ASCLEPIAS-CRITICALDUNE-7"
+  },
+  "drift": {
+    "enabled": true,
+    "layerOpacity": 1,
+    "palette": "dunelake",
+    "count": 28,
+    "slip": 0.4,
+    "flutter": 0.55,
+    "settle": 0.06,
+    "tuft": 2
+  },
+  "fiduciaries": {
+    "enabled": true,
+    "layerOpacity": 1,
+    "label": "ASCLEPIAS SYRIACA",
+    "pencil": "#39312a",
+    "width": 1,
+    "arrow": true,
+    "corners": false,
+    "caption": "wind · integrated | instantaneous | advected",
+    "target": [
+      -0.34,
+      0.42
+    ],
+    "from": [
+      0.35,
+      -0.3
+    ]
+  }
+};