Preserve embedded schematic images

[ShiboSoftwareDev]

Summary

• import native SchDoc image records into positioned schematic_graphic elements in the real-board round-trip fixture
• emit native record-30 image geometry and binary /Storage payloads from schematic graphics
• include graphic bounds in schematic sheet sizing
• pin the exact altiumts image-storage writer commit from Write embedded schematic PNG images altiumts#101
• add a focused NodeMCU source/round-trip SVG snapshot and assert the PNG SHA-256 is unchanged

Linked support

• Write embedded schematic PNG images altiumts#101 writes the native binary image storage
• Add schematic graphic placement metadata circuit-json#743 adds schematic graphic center and aspect-ratio metadata

Validation

• bun run typecheck
• bun run format:check
• bun test --max-concurrency 1 (25 tests, 0 failures)