Implement PDIP-8

[nailoo]

Here's are components on JLCPCB with this footprint: https://jlcsearch.tscircuit.com/components/list?package=PDIP-8

There may be reference dimensions/designs on the kicad viewer

This issue may be eligible for a $10 bounty from the TSCircuit team (please review!)

[buildingvibes]

/attempt #371

Implemented PDIP as a footprint variant that delegates to the existing DIP implementation. PDIP (Plastic Dual In-line Package) uses the same dimensions as standard DIP: 300mil row spacing, 2.54mm pitch.

PR: #504

[iprevail-io]

/attempt #371

Adding pdip and spdip as aliases for the existing dip footprint in normalizeDefinition(). PDIP is electrically identical to DIP — same through-hole pads, same pitch. The string parser just doesn't recognize the prefix today.

Changes:

• Add regex normalization: pdip → dip, spdip → dip
• Add 6 tests covering resolution, case-insensitivity, pad count, and SVG snapshot
• All 390 tests pass