feat: add blind and buried via board option

[seveibar]

Summary

• add the board-level allowBlindAndBuriedVias boolean
• default it to false, so ordinary boards request full-stack generated vias unless they explicitly opt in
• clarify that CopperPourProps.unbroken reserves a pour during autorouting while allowing vias to cross through antipads
• regenerate the public component and props references

Contract

allowBlindAndBuriedVias={false} is the default and restricts newly generated vias to the full board stack. Setting it to true allows the autorouter to generate blind and buried vias when the fabrication process supports them.

To keep an unrelated trace from splitting a copper pour, board authors can mark the pour unbroken; vias may still cross the reserved region using antipads.

Cross-repository stack

• Circuit JSON field: tscircuit/circuit-json#719
• core propagation and defaulting: tscircuit/core#3374
• autorouter enforcement: tscircuit/tscircuit-autorouter#2200

Validation

• bun test — 442 pass, 0 fail
• focused boolean tests — 2 pass, 0 fail
• bun run typecheck
• bun run check-circular-deps
• bun run build
• bun run format:check
• all four required documentation generators

[tscircuitbot]

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Thank you for your contribution! 🎉

PR Rating: ⭐⭐
Impact: Minor

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