[yapishu]

Summary

Adds first-class runtime selection to tx-types and migrates the crate to the upstream nockchain NounSpace/handle API, so the same source serves:

Consumer	Features	Runtime
ESP32 / nockster-esp	default-features = false	pokenoun (no_std, crypto-only)
Extension/app wallet (wasm)	std,embedded	vendored nockchain-minimal
Native consumer	std,native	upstream SWPSCO/nockchain @ 73877be

embedded and native are mutually exclusive; std requires exactly one. Both are compile errors if violated. The pokenoun re-export and the crypto-only no_std path are unchanged.

This is the point of tx-types: embedders and wasm consumers import it instead of the full nockchain tree, while native consumers still share the same wire types and hashing logic.

Runtime selection

Dependency sets are declared as aliased optional deps (nockapp-minimal / nockapp-upstream, etc.) and selected at the crate root with extern crate … as …. This keeps ::nockapp, ::nockvm, ::noun_serde, and derive-generated paths identical for both runtimes. Cargo does not allow a feature to switch dependency sources, so both sets live in this manifest.

BUILDING.md documents the matrix; the old use-local-nockchain.sh / use-git-nockchain.sh scripts and the consumer-side [patch] are removed.

Upstream API migration

• NounDecode::from_noun(&Noun, &NounSpace) everywhere, including the derive and nockchain-minimal.
• Handle-based traversal: noun.in_space(space).as_cell()/as_atom(), CellHandle::head()/tail(), AtomHandle.
• noun_space() on slabs/stacks, copy_into(root, &space), and space-aware TIP5/math entry points.
• Minimal nockvm/nockapp gained the new types/methods; existing 1-arg helpers remain where possible.

Correctness / parity fixes

From a line-by-line audit against nockchain 73877be:

• Fee accounting: count_note_data_words now matches Hoon (2n+1 atoms per note-data entry); previously 3n+1, overcharging minimum fees.
• Hash::from_b58: five divmods, reject non-zero high quotient and non-canonical spellings (exact re-encode).
• Hashing errors: removed fabricated Hash { [0; 5] } / cue→0 fallbacks; hashing returns Result, unbased/oversized atoms error.
• pokenoun hardening: checked sizes/shifts, allocation bounded by remaining input, 1<<20 walk budget, numeric atom comparisons (non-minimal spellings compare equal).
• Schnorr verification: reject zero chal/sig and non-canonical T8 limbs.
• Validator: V1 now returns UnsupportedVersion instead of silently Ok(()).
• Bythos: build_lock_merkle_proof selects stub below the phase and full at/above; callers pass a page/height.
• Decode safety: expect/assert on noun shapes replaced with errors; Witness::tim != 0 rejected; dead non-consensus TIP5 file removed.
• ZMap/ZSet: try_* variants added; legacy helpers no longer fabricate zero digests.

Breaking changes

• compute_tx_id_v1*, hash_noun_varlen, hash_hashable, V1 to_hash/to_hashable, and related hashing helpers return Result.
• build_lock_merkle_proof requires a page argument.
• Witness::from_noun rejects non-zero tim.
• TransactionValidationError::UnsupportedVersion added.
• embedded is the default backend; native consumers must opt out of defaults and select std,native.

Consumers updated in lockstep: siger-esp (std,embedded, host + wasm + thumb) and native consumers (std,native).

CI

• Targets are installed for the toolchain in rust-toolchain.toml (nightly-2026-04-03) via actions-rust-lang/setup-rust-toolchain.
• rustflags: "" so pre-existing warnings in vendored ibig are not promoted to errors.
• The regression job now passes end-to-end (no-std lib, no-std tests, hosted tests, vanity, browser assets, GPU-init tests).

Verification

• cargo check -p tx-types (default embedded+std)
• cargo test -p tx-types --lib — 80 passed
• cargo check -p tx-types --no-default-features and --target thumbv7em-none-eabihf — pass
• cargo check -p tx-types --no-default-features --features std,embedded — pass
• ... --features std,native — pass
• ... --features std,embedded --target wasm32-unknown-unknown — pass
• cargo test -p pokenoun — 11 passed
• vanity/pkh/gpu suites and browser asset build pass; PR CI is green.

Follow-ups

• pokenoun::jam still emits no backreferences (cue-compatible; byte size differs from nockvm::jam).
• Firmware (nockster-fw) requires the ESP/Xtensa toolchain; no_std was verified on thumbv7em-none-eabihf in CI.