feat(slice-2e): v0.0.35 — WASM investigation 3 layers (Layer 1+2 RESUELTOS, Layer 3 BLOCKED LLVM install)

Slice 2e WASM structural blocker investigation canonical sesión 3+ extended.
Substrate-wasm-builder re-enabled feature-gated. 3 layers explored canonical,
2 resueltos end-to-end, Layer 3 escalado a system-level LLVM install canonical.

## 3-layer findings canonical

- Layer 1 alloc/exchange_malloc duplicate → RESUELTO Slice 2c+2d (WASM_BUILD_STD=0)
- Layer 2 getrandom 0.2.17 wasm-incompat → RESUELTO Slice 2e (direct dep + custom feature)
- Layer 3 secp256k1-sys clang wasm32 target unsupported → BLOQUEADO (requires brew LLVM)

## Changes

- crates/origin-chain-runtime/Cargo.toml — substrate-wasm-builder feature-gated + getrandom workspace dep
- crates/origin-chain-runtime/build.rs — conditional WasmBuilder activation
- Cargo.toml workspace — getrandom = { version = "0.2", features = ["custom"] } workspace dep

## Layer 3 path forward canonical (Approach A recommended)

brew install llvm + configure CC_wasm32_unknown_unknown env var + retry build.
Pre-testnet Q3 2026 deployment infrastructure setup canonical canonical canonical.

## Investigation report canonical

Filed monorepo: docs/L7_roadmaps/SLICE_2E_INVESTIGATION_REPORT_V1.md (~280 LOC)
4 path forward approaches documented (LLVM install + pre-built secp256k1 + mock-WASM continue + upstream wait).

## Verification

- cargo test --workspace — 202 tests passing, 0 failures (NO regression)
- Default build unchanged (Slice 3 mock-WASM continues estable canonical)
- Feature-gated --features wasm-build activates substrate-wasm-builder para Layer 3 empirical testing

🔍 Slice 2e advanced canonical canonical. Path documented para Slice 2f future post-LLVM install.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/origin-chain-runtime/Cargo.toml

@@ -52,6 +52,11 @@ origin-chain-fees.workspace = true
 # (Inmutable #41 AGI DIDs Cross-Species Co-authorship)
 origin-chain-agent-identity.workspace = true
 
+# Slice 2e v0.0.35 — Direct getrandom canonical dep canonical para activate
+# `custom` feature canonical via Cargo feature unification (transitive
+# via const-random-macro → macro_magic → frame-support-procedural).
+getrandom = { workspace = true }
+
 # Phase 5.1 v0.0.29: origin-chain-governance wired runtime composition Index 10 canonical
 # (CHN-4 Foundation Treasury Governance, AI-Driven Human-Guarded canonical)
 origin-chain-governance.workspace = true
@@ -78,14 +83,17 @@ log.workspace = true
 serde_json.workspace = true
 
 [build-dependencies]
-# Slice 2c+2d findings registered (build.rs doc): WASM_BUILD_STD=0 resuelve
-# alloc/exchange_malloc pero descubre serde/std leak via types/std transitive
-# activation. Slice 2e future: [patch.crates-io] serde override o sp-io gate
-# adjust o stable2512-4+ upstream fix. Mientras tanto: no-op + Slice 3 mock-WASM.
-# substrate-wasm-builder = { workspace = true, optional = true }
+# Slice 2e v0.0.35 — Re-enabled substrate-wasm-builder for active investigation.
+# Slice 2c+2d findings: WASM_BUILD_STD=0 resuelve alloc/exchange_malloc pero
+# descubre serde/std leak via types/std transitive activation. Slice 2e attempt:
+# patch.crates-io serde override + types/std isolation.
+substrate-wasm-builder = { version = "26.0.1", optional = true }
 
 [features]
 default = ["std"]
+# Slice 2e v0.0.35 — WASM build feature gate canonical.
+# Enable with `--features wasm-build` para build real WASM_BINARY canonical.
+wasm-build = ["substrate-wasm-builder"]
 std = [
     "origin-chain-types/std",
     "sp-core/std",

crates/origin-chain-runtime/build.rs

@@ -1,28 +1,39 @@
-//! # Build script — Slice 2d findings registered, deferred future session
+//! # Build script — Slice 2e v0.0.35 canonical investigation
 //!
-//! Slice 2c attempts 1-4 (Slice 2b 2026-05-21): direct serde / pin / profile /
-//! build_using_defaults — ALL NO solved alloc/exchange_malloc conflict.
+//! ## History
 //!
-//! Slice 2c attempt #5 + Slice 2d (sesión 2 cont 2026-05-24):
-//! - WASM_BUILD_STD=0 explicit override → alloc/exchange_malloc RESUELTO
-//! - NEW layer surface: panic_impl duplicate via serde/std leak transitive
-//! - Diagnostic via cargo tree --target wasm32 -e features: identified
-//!   `origin-chain-types feature "std"` → `serde feature "std"` activation path
-//! - Root cause: algún dep transitive activates types/std en wasm32 build
-//!   incluso con --no-default-features (probable: macro expansion automation)
+//! - **Slice 2c attempts 1-4** (2026-05-21): direct serde / pin / profile /
+//!   build_using_defaults — ALL NO solved alloc/exchange_malloc conflict.
+//! - **Slice 2c attempt #5 + Slice 2d** (2026-05-24): WASM_BUILD_STD=0 explicit
+//!   override → alloc/exchange_malloc RESUELTO. NEW layer: panic_impl duplicate
+//!   via serde/std leak transitive.
+//! - **Slice 2e v0.0.35** (2026-05-26): re-enable substrate-wasm-builder canonical
+//!   con `wasm-build` feature gate. Investigate [patch.crates-io] serde override
+//!   + types/std isolation empirical.
 //!
-//! ## Path forward Slice 2e future
+//! ## Usage canonical
 //!
-//! Requires architectural fix:
-//! - [patch.crates-io] serde override con strict no-std
-//! - O sp-io feature gate adjust
-//! - O wait stable2512-4+ upstream fix
+//! - Default (no feature): build script no-op, mock-WASM Slice 3 fallback active.
+//! - `--features wasm-build`: substrate-wasm-builder activated, real WASM_BINARY
+//!   build attempted. WASM_BUILD_STD=0 must be set to avoid alloc duplicate.
 //!
-//! Mientras Slice 2e land, build script no-op + Slice 3 (v0.0.13) mock-WASM
-//! fallback (chain_spec.rs en node crate via serde_json puro) sigue siendo
-//! path estable. Cross-pillar consumers (Trinity/Codex/Ethos/Atelier) ya
-//! pueden consumir ChainSpec JSON output sin necesidad runtime WASM real.
+//! ## Path forward post-Slice 2e canonical
+//!
+//! Si serde/std leak resolved → Phase 3 pallet-revive smart contracts unblocked
+//! Si NOT resolved → document next attempt path (upstream Substrate stable2512-4+
+//! wait OR sp-io feature gate audit deeper OR alternative WASM builder).
 
+#[cfg(feature = "wasm-build")]
 fn main() {
-    // No-op — Slice 2e future resolves WASM_BINARY. Slice 3 mock-WASM estable.
+    substrate_wasm_builder::WasmBuilder::new()
+        .with_current_project()
+        .export_heap_base()
+        .import_memory()
+        .build();
+}
+
+#[cfg(not(feature = "wasm-build"))]
+fn main() {
+    // No-op — Slice 3 mock-WASM fallback active.
+    // Enable real WASM build with `cargo build --features wasm-build`.
 }