Interactive haunted jelly island diorama with Halloween scenes

[Note: the creator shared a partial prompt. Wording below is theirs.] GOAL: Build "Hollow Isle Jelly", a Halloween piece for my "Material Studies" series of interactive jelly dioramas: a haunted island at night, set inside a wobbling block of translucent jelly. MOTION: FORMAT - One self-contained HTML file. Raw WebGPU + WGSL, no libraries, no external assets (fonts: system serif/sans/mono stacks). If WebGPU is missing, show a clean fallback card instead of a blank page. - Everything procedural: meshes built in JS, textures computed in shaders, sounds synthesised with Web Audio. THE JELLY BLOCK - A square block of jelly (the sea) sits on a paper-studio floor. The island rises out of it. The block's cut faces show candy-coloured strata at the bottom and, above them, dark rock, clay and silt. - Buried in the cut faces (drawn in the face shader): a sunken chest of gold, an anchor, a skull and crossbones, a sea serpent's skeleton, a bottle with a message, and stray bones. - Real jelly behaviour: a heightfield water sim (drag across the surface to make ripples), the whole block wobbles and can be tipped by dragging its side, and there are Firmness and Wave damping sliders. - Rendering: refraction with absorption (Beer–Lambert) and back-scatter, caustics on the bed, a sun/moon shadow map, fresnel reflections, 4× MSAA, HDR with a soft shoulder tone map and dither. NIGHT - It is always night: a dark navy studio, twinkling stars, and a painted moon whose reflection makes a glittering moon path on the jelly's top. - Moonlight is cool, dim and blue, and every light source throws a warm pool of light: pumpkins, lanterns, candles, the fire. The witch's windows and the open crypt throw green light (up to ~32 point lights in a uniform array). - Foam, ambient light, scattering and rim light must all respect the night. Nothing should look like daylight. THE ISLAND - A hill topped by a ruined stone chapel with a bell tower. Its bell actually swings. - A graveyard on the slope behind an iron railing with a gate between stone pillars. Crooked headstones of varied shapes (round, cross, slab, obelisk, angel), grave mounds, little candles. - A stone crypt sunk into the hill, with a hinged iron door and a black cat with glowing eyes on its roof. - A witch's hut on stilts by a black peat bog. The bog has reeds, stumps and drifts of green scum. The hut has green-glowing windows and a smoking chimney, and a cauldron hangs on a tripod over a fire. - A tilled pumpkin patch with ~12 carved jack-o'-lanterns and a scarecrow with a pumpkin head and flapping rags. - Dead twisted trees holding their last orange leaves, crows, and cobwebs in the chapel door, under the hut's eaves, on the railing and in the tree forks. - A wooden jetty with a lantern, a weathered rowboat with a stern lantern, path lanterns, a shingle shore, boulders and sea stacks. - Life: fish in the sea, crows, bats (they pour out at midnight), drifting fog, falling leaves, and 5 children in costumes (sheet ghost, pumpkin, little witch, skeleton suit, vampire). THREE EVENTS (big butto