Inline <footprint> components get no silkscreen reference designator

Summary

A component using an inline <footprint> gets no silkscreen reference designator, while the same component using a string footprint does.

// string footprint
<chip name="U1" footprint="soic8" />
// → pcb_silkscreen_text: ["U1"]

// inline footprint
<chip name="J1" footprint={
  <footprint>
    <smtpad pcbX={-0.5} pcbY={0} width="0.55mm" height="1.1mm" shape="rect" portHints={["pin1"]} />
    <smtpad pcbX={0.5}  pcbY={0} width="0.55mm" height="1.1mm" shape="rect" portHints={["pin2"]} />
  </footprint>
} />
// → pcb_silkscreen_text: []

Verified directly against current main:

STRING: silkscreen_text= [ "U1" ]   cad_component= 1
INLINE: silkscreen_text= []         cad_component= 1

The board renders and exports without any error, so the missing designator only shows up when you look at the silkscreen — or when an exporter needs it. This is the root cause behind tscircuit/circuit-json-to-kicad#51 ("Footprint files are missing things like reference designator"): the KiCad converter can't emit fp_text reference from data that isn't in the circuit JSON.

Cause

NormalComponent._addChildrenFromStringFootprint() has a single typeof footprint === "string" branch:

if (typeof footprint === "string") {
  const fpCircuitJson = fp.string(footprint).soup()
  const fpComponents = createComponentsFromCircuitJson(
    { componentName: this.name ?? this.componentName, ... },
    fpCircuitJson,
  )
  this.addAll(fpComponents)
}

Footprinter emits a pcb_silkscreen_text placeholder, and createComponentsFromCircuitJson rewrites its text to the component name:

text: componentName || elm.text,

Inline JSX footprints never enter that function, so nothing ever creates the designator for them.

Expected

An inline footprint should get the same reference designator a string footprint gets, placed clear of the footprint bounds, on the component's layer, and without duplicating one the footprint already declares.

PR follows.

Start in NormalComponent._addChildrenFromStringFootprint() and compare the string-footprint path with inline child handling. Check how createComponentsFromCircuitJson rewrites pcb_silkscreen_text and how the inline footprint is represented. Done means inline footprints produce one component-name silkscreen reference, placed clear of the footprint bounds, without duplicating an existing declaration.