Ryan Malloy c2197f6fe6 Add star-topology layout optimization for single-module diagrams
Three-pass optimization eliminates cable crossings:
1. Order boundary components by average header pin position
2. Regroup header pins by boundary component (reduces inter-cable crossings)
3. Reorder boundary component pins to parallel header (eliminates within-cable
   crossings)

Safety hardening from Apollo review:
- Duplicate header pin deduplication (prevents silent mapping corruption)
- Connection structure validation at entry
- Fan-out averaging for component pins connected to multiple header pins
- Explicit ValueError on pin remapping failures with diagnostic context

145 tests passing (was 130).
2026-02-13 03:07:50 -07:00
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