NanoDSL: End-to-end support for HStack wrap + child flex

[phodal]

Goal

• Make NanoDSL authoring support: HStack(wrap=true or wrap="wrap") and child flex= end-to-end.

Scope

• Spec: declare wrap on HStack and flex on common layout/container nodes (at minimum Card/VStack/SplitView/Form/Component).
• Parser (IndentParser): parse wrap for HStack and flex for supported nodes from args and indented props.
• IRConverter: emit props.wrap and props.flex into NanoIR.
• Renderers:
  • Compose: use existing wrap/flex logic (already implemented) but ensure it is reachable from DSL.
  • HTML: implement wrap via CSS (flex-wrap) and flex via style="flex: 1 0%" or equivalent.
• Tests: add/extend cross-platform IR conversion tests to cover wrap/flex output.

Acceptance

• Given NanoDSL:
  component FlexWrapDemo:
  HStack(wrap=true):
  Card(flex=1):
  Text("A")
  Card(flex=2):
  Text("B")

  IR contains HStack.props.wrap=true and child Card.props.flex=1/2.
  Compose renderer wraps when wrap=true and allocates weights accordingly.
  HTML renderer wraps and respects flex ratio.

Notes

• Keep behavior minimal; avoid new UX features beyond wrap/flex.