Make pcb footprint overlap message stable

[posthog]

Problem

• Board layout DRC violations reached error tracking as a new, ungroupable issue for almost every user circuit — one defect fragmented across thousands of distinct message strings, which buries real regressions in the inbox.
• checkPcbComponentOverlap built the message from user component designators: `${elem1.type} ${elem1Description} overlaps with ${elem2.type} ${elem2Description}` — so R1.pin2 / C1.pin1 and every other designator pair minted a new string.
• The identifying data was already available in structured fields (pcb_smtpad_ids, pcb_plated_hole_ids, pcb_hole_ids), so the designators added nothing the error object did not already carry.

Changes

• Build the message from the two element types only, sorted for order stability: pcb_smtpad overlaps with pcb_smtpad. The template is now stable, so all overlaps of the same type pair collapse into one issue.
• The specific overlapping elements stay in the structured *_ids fields on the error object — no information is lost.
• Remove the now-unused formatOverlapElementDescription helper and its get-readable-names imports.

- message: `${elem1.type} ${elem1Description} overlaps with ${elem2.type} ${elem2Description}`,
+ const [firstType, secondType] = [elem1.type, elem2.type].sort()
+ message: `${firstType} overlaps with ${secondType}`,

Scope

• This repo change stops the fingerprint explosion at the source (the message).
• The second, independent half — routing DRC findings away from the throwing Renderable.renderError path so a bad board reports a diagnostic instead of an uncaught exception — lives in tscircuit/core and is not part of this PR.

Tests

• Updated the affected SVG snapshots (the message is rendered when shouldDrawErrors is on) and the repro01 inline assertion; added a check that the structured pcb_smtpad_ids still carry both elements.
• Full suite passes: 142 tests.

Agent context

• Checked open PRs and issues on tscircuit/checks; none touch this message or the overlap fingerprinting.

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Created with PostHog Desktop from this inbox report.