fix(screenmaps): refine HydroPack EL geometry

[zackees]

Summary

• make each HydroPack EL triangle 3 cm wide and equilateral
• make the center EL wire 1 cm wide by 6 cm tall
• update the fixture and Playwright assertions to preserve the physical dimensions

Validation

• npm run test:integration -- create-hydropack-el
• node --import tsx --test tests/unit/manifest-presets.test.ts
• git diff --check