Add full ERC-7730 clear signing on alpha

[BitHighlander]

Goal

Implement complete active ERC-7730 v2 clear signing on alpha using reusable signed definitions by default. KeepKey’s transaction-bound live signer remains available only for facts that signed metadata and device-side decoding cannot establish.

Implemented in this draft

• architecture, trust boundaries, conformance target, protocol ownership, and verification gates
• allocation-free bounded C ABI interpreter with a flat forward-only type graph
• recursive tuples and fixed/dynamic arrays
• uint/int widths, address, bool, fixed/dynamic bytes and UTF-8 string validation
• canonical padding, offset, packed-tail, overlap/gap, trailing-byte and resource-limit rejection
• positive/negative tuple/array path indices
• native adversarial unit coverage for recursive decoding and malformed encodings

Canonical protocol dependency

• Add canonical ERC-7730 compiled definition protocol device-protocol#45
• protocol commit: 509dec6
• alpha intentionally remains on its current protocol pin until feat: add TRON and TON chain support #45 merges to the fork’s master; it will then pin that master commit

Verification so far

• strict C11 compile with -Wall -Wextra -Werror
• native GTest slice: 4/4 passed
• complete firmware target compiled through all C/C++ objects; the local macOS link then hit the repository’s pre-existing nanopb field-alignment linker failure
• protocol: protoc validation and npm generated JS/JSON build passed

Remaining before full-support claim

Signed envelope/catalog verification, compiled-program parser, display/path/condition/formatter VM, calldata signing integration, shared streamed EIP-712 tree, host compiler/resolver/cache, registry and adversarial corpora, fuzzing, OLED evidence, ARM/bitcoin-only/full gates, and audit review.

Reference implementation: Trezor current main dc99b24533b390b305682730c027231bf2244dc2.

This is alpha-only and does not modify a bootloader, storage format, or release branch.

[BitHighlander]

Canonical dependency chain advanced with full repository authority:

• device-protocol feat: add TRON and TON chain support #45 merged to master (753f286)
• discovered alpha dice fields were not on master; reconciled them through device-protocol fix(zcash): update transparent branch ID from Sapling to NU6 #46, merged master 3280f4b
• python-keepkey fix(solana): display full base58 addresses #88 merged to master 50b18d1 with generated ERC-7730 bindings and protobuf 3.20 compatibility tests
• alpha now pins both canonical fork masters in 3945f200f
• local nanopb regeneration initially rejected callback fields; fixed all new bytes fields with static max sizes
• kkfirmware target builds successfully with the new canonical protocol pin

Next implementation unit remains the signed-envelope/program parser and session streaming state machine.