fix: straighten segments left slightly off-axis by imprecise pin input

[DPS0340]

The defect

Two boards render a visibly skewed trace. Measured across every imported bug report:

bug-report-20260717T022934Z  diagonalSegs=1
bug-report-20260716T144856Z  diagonalSegs=1

Schematic traces are orthogonal by construction, so any non-axis-aligned segment is a bug. The offenders:

SJ2.1-R3.2: (5.3999,1.9500) -> (5.4000,1.5000)   dx=6.22e-5  dy=-4.50e-1
JP2.1-R5.1: (5.4999,-8.4500) -> (5.5000,-9.2000) dx=6.22e-5  dy=-7.50e-1

Identical dx on both, which pointed at the input rather than the routing. It is:

SJ2.1  x = 5.3999378      <- off by 6.22e-5
R3.2   x = 5.4

A pin coordinate arrives a fraction of a mil off its neighbour. Tracing it through the pipeline, the skew is present from schematicTraceLinesSolver onward and no stage corrects it — the solvers assume orthogonality rather than enforcing it, so nothing notices.

Fix

A TraceCleanupSolver pass that snaps segments within 1e-3 of an axis onto it exactly, collapsing the smaller deviation and moving the later point so the trace's starting pin stays where the input put it.

On the threshold: 1e-3 is two orders of magnitude below LABEL_SEARCH_STEP (0.1), the smallest deliberate jog any solver makes. A genuine diagonal is never flattened — the guard requires one axis to be within tolerance while the other is not.

I put it in TraceCleanupSolver rather than in cloneAndCorrectInputProblem deliberately. Snapping pins at input time would move the pins themselves, which affects chip bounds and every downstream placement decision; snapping the rendered segment fixes the symptom without perturbing the problem the solvers were given.

Result

diagonal segments:  2 -> 0

And confirming nothing else moved:

labels inside chips:  8 -> 8
label-label overlaps: 7 -> 7
trace crossings:     40 -> 40

Verification

• Full suite 148 pass / 0 fail / 4 skip, tsc --noEmit clean, biome clean.
• 4 snapshots regenerated. I checked the diff rather than accepting it: the change is exactly the intended one —

  - data-points="5.3999378,1.9499… 5.4,1.5000…"
  + data-points="5.3999378,1.9499… 5.3999378,1.5000…"
  

  the x now matches and the segment is vertical. No other geometry changed.
• Note biome check --write reformats 9 unrelated files in this directory; I reverted those so the diff stays reviewable.

Diff: 1 new file, 1 source file touched, plus the 4 snapshots. Independent of my other open PRs.

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Project	Deployment	Actions	Updated (UTC)
schematic-trace-solver	Ready	Preview, Comment	Jul 26, 2026 4:37am