pinHeader pinCount accepts fractional, zero, negative and infinite values

[DPS0340]

Summary

pinHeaderProps.pinCount is declared as a bare z.number(), so it accepts fractional, zero, negative and infinite values. A fractional count produces a header whose port count and pad count disagree, and nothing reports it.

<board width="30mm" height="30mm">
  <pinheader name="H1" pinCount={2.5} pcbX={0} pcbY={0} />
</board>

pinCount	source_ports	pads	errors
2	2	2	0
2.5	2	3	0
3	3	3	0
3.7	3	4	0
4	4	4	0

Every whole number agrees. Every fractional one produces a component with a pad that has no port behind it — the same shape of defect as a phantom pin, and it renders and exports without complaint.

Zero and negative counts fail too, just later and less clearly:

pinCount=-4  →  0 ports, 0 pads, 1 error: pcb_missing_footprint_error
pinCount=0   →  0 ports, 0 pads, 1 error: pcb_missing_footprint_error

pcb_missing_footprint_error points at the footprint. The mistake was the pin count.

At the schema level:

pinHeaderProps.safeParse({ name: "H1", pinCount: 2.5 })        // success ✅
pinHeaderProps.safeParse({ name: "H1", pinCount: -4 })         // success ✅
pinHeaderProps.safeParse({ name: "H1", pinCount: 0 })          // success ✅
pinHeaderProps.safeParse({ name: "H1", pinCount: Infinity })   // success ✅

(NaN is already rejected — zod's z.number() excludes it but not Infinity.)

Cause

lib/components/pin-header.ts:

export const pinHeaderProps = commonComponentProps.extend({
  pinCount: z.number(),
  ...

A count of physical pins is inherently a positive integer, but nothing says so. The repo already uses the right idiom elsewhere — lib/components/analogacsweepsimulation.ts has z.number().int().positive() for sampleCount and samplesPerInterval.

Expected

pinCount should be a positive integer, rejected at parse time with a message naming the prop, rather than producing a mismatched component or surfacing later as an unrelated footprint error.

Valid counts must keep parsing to the same value — this shouldn't change behaviour for any real header.

PR follows.