feat: add hidden wt animate easter eggs (duck pond, crab, hatching egg)

[johnpangalos]

What

Two hidden commands — deliberately absent from --help:

• wt animate — 8-bit-style pixel animations in the terminal. The default is a duck paddling across a pond: four depth-shaded water layers with wave crests and highlight streaks drifting at different parallax speeds, a trailing wake, a vertical bob, an occasional blink, a lily pad riding the drift, sun and a cloud. wt animate crab plays a red crab scuttling along the beach (a nod to the Claude crab).
• wt animate2 — the prequel: an egg on a grassy meadow wobbles, cracks, pops its top, and hatches into a duckling that waddles off flapping. Also reachable as wt animate egg.

wt animate                 play the duck until Ctrl-C
wt animate --list          list animations
wt animate --frames <n>    render n frames and exit (non-tty default: 1)
wt animate --color         force color when piping; NO_COLOR wins over everything
wt animate2                the egg hatch, same flags

How

Each animation is a pure frame(tick, cols) returning a pixel grid of palette keys. Rendering uses the half-block trick: every pair of pixel rows becomes one line of ▀ with 256-color foreground (top pixel) and background (bottom pixel), doubling vertical resolution. The player hides the cursor, redraws in place with erase-to-EOL, and restores the cursor on exit or Ctrl-C; non-tty/NO_COLOR falls back to one plain character per pixel pair.

Purity keeps every frame deterministic and unit-testable. docs/animations.md documents the technique plus ideas for future scenes.

Tests

49 new assertions-heavy tests in tests/animate.test.ts: grid purity/shape/width, duck visibility and leftward motion, water layering and movement, hatch-story phases, both renderers, player escape-code behavior, and e2e runs of the compiled binary (--list, --color vs NO_COLOR, unknown names, bad flags, and both commands staying out of --help). Full suite: 94 pass.

🤖 Generated with Claude Code