VibeSchem v0.6.0

• Gravity. Sand, red sand, gravel, concrete powder, anvils and the dragon egg fall when what
  holds them goes, as entities with the game's physics (2 gt wait, gravity 0.04, drag 0.98): they
  land on the first collision box below (on top of a fence, 1.5 high), break into an item inside a
  torch, a slab or another block they can't replace, and concrete powder hardens in water.
  Suspicious sand and gravel shatter; a stalactite falls when its block goes. In the viewer the
  falling blocks glide down.
• Water and lava flow like in the game: down first, then toward the nearest drop, 7 blocks
  for water (1 every 5 gt), 3 for lava (1 every 30 gt); new sources between two; water washes
  redstone away; lava and water make obsidian, cobblestone and stone; waterlogged blocks spill.
  The viewer draws flowing liquids lower as they spread.
• Items move. Hoppers pull from above and push where they face (1 item every 8 gt, 7 gt per
  hopper along a chain, locked while powered), droppers push into containers, dispensers pour and
  pick up water and lava with buckets. Comparators follow the contents, and a build's rest state
  saves them.
• Click it like in Minecraft. Right-click a lever, button, pressure plate, target (power by
  where you hit it), lectern, trapped chest, lightning rod, sculk sensor, daylight detector, note
  block or door in the viewer and the simulation starts by itself; the cursor shows what you can
  use. The same in tests: {"use": [x,y,z]} steps on plates, shoots targets and opens trapped
  chests too. New inputs: trapped chests, lightning rods, detector rails; containers can be read as
  outputs.
• Labels you can hide: the I/O labels on the model show every bit, only the names, or nothing
  (the tag button or I), remembered between sessions. A bus is labelled once, its other bits by
  number.
• Fixed: the viewer didn't recognise blocks under the cursor when the camera was inside the
  build's bounding box (zoomed in close).