Second POC for redoing Layout Batch 1 demos. Mirrors `box`'s canonical
shape adapted for a flex container:
- 7 container-side controls (direction, align, justify, wrap, gap,
padding, inline) — chips for unions, number for space tokens,
switch for the boolean.
- API tab separates "Container props (Flex-only)" from "Inherited
from Box" with a forward-link.
- Cross-references: lede + API call out that item-side props
(alignSelf, gridColumn, …) live on the child `<Box>`, and that
Stack / Group are direction-specific helpers.
- Reference comparison row reflects the Radix Themes split (item vs
container) and notes Chakra's `HStack`/`VStack` map to UIX `Stack`.
Adds `src/uix/morfo/components/flex.ts` (scope `eidos`, 1 part, 0
events, mirrors box.ts justification).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>