Oxygen 0.2.1

Added

• The desktop app updates itself on Windows and Linux: a new version downloads in the background and installs the
  next time Oxygen restarts, or right away from Restart to update in the status bar (it asks first if anything
  is unsaved). Help › Check for updates… looks now, and Settings › General can turn automatic downloads off.
  On macOS it says when there's a new version and links to it. This starts with the first release after 0.2.0:
  install that one by hand.
• The web app tells a tab left open when a newer version is out, and reloads into it on request.
• MCP servers installed from the release zip tell the agent when a newer release is out, and how to update.
• Effects on an entity use real locators. Import them from a model's .geo.json (worked out through its bones)
  or make your own with an offset and rotation as a geometry file writes them. The viewport draws the axes the
  effect gets. The stand-in entity also has a scale, a collision box size for entity_aabb, a facing, a time
  when it goes away, and a Follows it switch for bind_to_actor: false. The MCP tools take all of these as an
  entity option.
• The Inspector's texture area shows a small picture of what the particle draws (the area, or a flipbook's first
  frame). Clicking it opens the Texture panel.
• The Context panel takes temps (t.size) as inputs too, as a parent's event leaves them before it spawns the
  effect, and context values (c.size), which every expression can read. evaluate_molang takes contexts too.
• The Debug panel shows the values a selected particle's own expressions left on its turn in the frame, such as the
  index it took from a counter, next to what the emitter's shared variables hold now.

Changed

• Effects on an entity now behave as measured in the game (test pack e01–e12):
  • A locator flips the effect's axes: an unturned locator points Y down and X to the entity's left. Without a
    locator X points to the entity's right and Z behind it.
  • An emitter on an entity holds 1,000 particles, not 10,000.
  • The entity's movement adds no speed to its particles, even with emitter_local_space velocity on.
  • World-space effects on an entity take relative_position from the world origin.
  • entity_aabb fills the entity's box at the emitter, in the emitter's axes.
  • Entity queries read 0 in an emitter's creation expression. q.position is where the entity stands.
  • When the entity goes away, particles in its space go with it.
• The entity's facing uses Minecraft's yaw: 0 is south, 90 west.
• The Scene panel no longer offers made-up attachment points (head, hands and so on) as locators. Scenes saved
  with them keep them as locators at the same places.

Removed

• The Flip Y switch for locators. Every locator flips its axes in the game, so Oxygen always does.

Fixed

• The start screen shows the keys you bound for New effect, Open files and Commands.