Add TOLL-8 footprint

[Abse2001]

Summary

• add an explicit toll8 footprint variant
• model its eight leads, drain bridge, and large drain pad
• add a C2979263 regression test and SVG snapshot

Motivation

HYG015N10NS1TA (JLCPCB C2979263) uses the distinct TOLL-8 copper topology. Treating the large drain land as an offset thermal pad in a two-sided IC family reached only 86.22% copper IoU.

Implementation

The first TOLL-8 variant encodes the verified land pattern directly. It deliberately avoids speculative controls for each lead, bridge, and drain dimension until additional real TOLL variants require them.

Validation

• bun test tests/toll.test.ts: 1 passed
• bun run build
• C2979263 copper IoU: 99.997%
• new SVG snapshot for the real TOLL-8 footprint