v0.1.3

• Dark canvases now theme the built-in controls automatically: DARK_THEME needs no --gb-*
  setup, and a light graph embedded in a dark page keeps light controls.
• The legend expands and collapses with the same 220ms easing as search, and respects reduced
  motion.
• README's "Try it yourself" now leads with three ways in — demo, agent + npx glassbrain,
  React — plus the one-line prompt and examples; the demo links to the repo by name.
• docs/cli.md says what the layout benchmark does and does not measure.