Handle connected copper in fanout clearance

[seveibar]

Summary

• add the exact serialized clad1 RP2040 fanout input as dataset06
• fix clearance validation so copper whose connectedTo list contains the connection name is not treated as a foreign obstacle
• add a focused regression for crossing same-connection copper
• render failed datasets as visibly labeled best-attempt snapshots and check in the clad1 image

Verified improvement

The exact fixture contains:

• 132 top-layer connections and 132 atomic buses
• 265 mixed-footprint obstacles
• one shared component-area boundary
• escapeLayers: ["top"]
• compactBusTracks: true
• borderDistribution: "even"
• no alternate escape layer

Same-connection copper awareness improves the deterministic best attempt from 35/132 to 37/132 connections.

The snapshot is intentionally labeled INCOMPLETE 37/132; this PR does not claim a complete route.

Remaining fanout features surfaced by the repro

1. Non-monotone single-layer escapes. At least one left-targeted connection has the RP2040 pad field and exposed pad directly to its left. A valid escape must initially move away from the requested boundary, route around the copper, and then turn back. The current lane and push/shove solvers are monotone.
2. Mergeable multi-terminal electrical nets. Repeated source_net_*::fanout:* terminals are currently allocated as mutually exclusive traces even when they share one netConnectionName. Routing them as one mergeable tree would remove artificial same-net congestion.

As a cross-check, the capacity autorouter's tiny-hypergraph pipeline reduced the full case to two unresolved high-density nodes at effort 2, but did not produce a complete accepted route after about 4.5 million iterations. That result is not committed or counted as success.

Refs #4.

Validation

• bun test — 22 passing
• bun run typecheck
• bun run format:check
• git diff --check
• visual inspection of docs/images/dataset06/sample001.png

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
fanout-solver	Ready	Preview, Comment	Jul 28, 2026 2:26am

[tscircuitbot]

---

Thank you for your contribution! 🎉

PR Rating: ⭐⭐⭐
Impact: Major

Track your contributions and see the leaderboard at: tscircuit Contribution Tracker

---