A bot's identity was one of seven hues, and the hue picked both its colour
and its stone shape. Now its colour is free and its stone is its own:
- `bots.color` holds any `#rrggbb`, `bots.stone` the flat-cut shape it's
drawn on. `bots.hue` stays as the palette column they replaced, read only
as a fallback; `src/scripts/move-bot-colour-to-owners.ts` backfills an
install from it (safe to rerun).
- `src/utils/bot-color.ts` is the only place a colour is validated or
resolved (`resolveBotColor`/`resolveBotStone` carry the old hue forward,
`botColorNeedsPaperFace` flips the eyes to paper on a very dark body), and
`src/utils/bot-stone-props.ts` gives every row its props, so a row saved
before this still renders as it did.
- `BotStone` takes the colour as the body's SVG `fill`, the one documented
exception to the token rule: an arbitrary hex has no token to point at.
`UnreadDot` follows it.
- The picker keeps the palette tiles (still shape and colour together) and
adds a native swatch and a hex field, so a custom colour keeps its stone.
Same place as before: the header avatar's modal and Settings > Bots, for
crew managers. The coordinator stays hue-less.
- A recolour reaches other open tabs through `pushBotUpdated`.
