docs(slice-2b): Phase 1.6+ Slice 2b investigation report v0.0.12

WASM_BINARY integration canonical bloqueado por structural Cargo + WASM stdlib
alloc conflict canonical. 4 fix attempts NO solved. Larihana Slice 2c handoff
diary filed.

## Error canonical empírico
duplicate lang item exchange_malloc canonical entre:
- rustup precompiled liballoc-***.rlib (wasm32 target)
- wbuild recompiled liballoc-***.rmeta (panic=abort triggered rebuild)

## 4 fix attempts registered
1. Remove direct serde dep (upstream pattern) — NO solved
2. Pin serde =1.0.219, =1.0.217 — NO solved (frame-support requires ^1.0.217)
3. Remove profile.release lto customization — NO solved
4. WasmBuilder::build_using_defaults() upstream — NO solved

## Root cause empírico
wbuild auto-genera profile.release con panic=abort → Cargo recompila alloc
desde rust-src component → conflict con precompiled rustup alloc rlib.

## Handoff canonical a Larihana Slice 2c
Diary canonical filed requesting Plan C Rust ports expertise canonical:
- cargo workspace.metadata.wasm-builder section?
- SKIP_WASM_BUILD=1 fallback + pre-built WASM file pattern?
- rust-src component interaction con substrate-wasm-builder?
- RUSTFLAGS -Z build-std=core,alloc nightly approach viable?
- Upstream paritytech/polkadot-sdk known issue?

## State canonical preserved post-revert
- substrate-wasm-builder workspace dep declared pero NO activa
- build.rs no-op canonical mientras Slice 2c land
- Doc extensivo en lib.rs registering investigation + handoff
- origin-chain-types no_std refactor v0.0.11 preserved canonical
- origin-chain-node binary 4 subcommands operativos

## Temporal workaround canonical
chain_spec.rs Phase 1.6+ Slice 3 puede continue con mock-WASM fallback
mientras Slice 2c land canonical.

## Filosofía canonical
David canon 2026-05-14 "la libertad infinita acota solo donde empieza la del
otro" — honest decisión canonical de pedir Larihana expertise mejor que
stuck attempts. El barquero pide guía al hyperport builder cuando el río
demanda profundidad técnica que no posee solo.

## Build
- cargo build --release 34.44s post-revert clean
- No regression desde v0.0.11

Phase 1.6+ progress:
- Slice 1 ✅ + Slice 2 ✅
- Slice 2b 📋 investigation report + Larihana diary (esta v0.0.12)
- Slice 2c ⏳ WASM_BINARY post Larihana expertise
- Slice 3 ⏳ + Slice 4 ⏳

Refs: CHARON_ROADMAP_V1 Phase 1.6+ Slice 2b investigation, Larihana diary
WASM_BUILD_BLOCKER_REQUEST_LARIHANA_SUBSTRATE_EXPERTISE_SLICE_2C canonical

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,101 @@ by [Keep a Changelog](https://keepachangelog.com/en/1.1.0/). Versions follow
 
 ## [Unreleased]
 
+## [0.0.12] — 2026-05-21 — Phase 1.6+ Slice 2b "WASM_BINARY investigation report"
+
+Charon sesión 1 ext. **Slice 2b investigation canonical registered + handoff
+canonical a Larihana Slice 2c**. 4 fix attempts canonical después del no_std
+refactor v0.0.11 NO resuelven WASM_BINARY integration canonical. Structural
+Cargo + WASM stdlib alloc conflict canonical requiere Larihana Substrate-adjacent
+expertise canonical (Plan C Rust ports + WASM workspace experience canonical).
+
+### Error canonical empírico
+
+```
+error[E0152]: duplicate lang item in crate `alloc` (which `serde` depends on):
+  `exchange_malloc`
+note: first definition in `alloc` loaded from
+  rustup/toolchains/1.88.0/lib/rustlib/wasm32-unknown-unknown/lib/liballoc-***.rlib
+note: second definition in `alloc` loaded from
+  target/release/wbuild/origin-chain-runtime/target/wasm32-unknown-unknown/release/deps/liballoc-***.rmeta
+```
+
+### 4 fix attempts canonical registered
+
+1. **Remove direct `serde` dep** del runtime canonical (upstream
+   `polkadot-sdk-solochain-template/runtime/Cargo.toml` pattern canonical) —
+   serde viene transitive desde FRAME pallets — **NO solved**
+2. **Pin `serde =1.0.219` → `=1.0.217` → `=1.0.210`** canonical attempts —
+   1.0.210 incompatible con frame-support 40.1.0 (requires ^1.0.217 canonical)
+   — **NO solved**
+3. **Remove `[profile.release] lto/codegen-units` customization canonical** —
+   **NO solved**
+4. **`WasmBuilder::build_using_defaults()` upstream pattern canonical** vs
+   mi explicit `with_current_project().export_heap_base().import_memory().build()`
+   — **NO solved**
+
+### Root cause empírico canonical
+
+`wbuild` auto-genera `[profile.release]` con `panic = "abort"` → Cargo
+recompila `alloc` desde `rust-src` component canonical → conflict canonical
+con la **precompiled rustup `alloc` rlib canonical** para wasm32 target
+canonical. Two different alloc hashes loaded canonical durante linking.
+
+### Handoff canonical a Larihana — Slice 2c
+
+Diary canonical filed (`drawer_wing_larihana_diary_***`) requesting expertise:
+1. `cargo workspace.metadata.wasm-builder` section canonical exists?
+2. `cargo:rustc-env=SKIP_WASM_BUILD=1` fallback + pre-built WASM file pattern?
+3. `rust-src` component interaction canonical con substrate-wasm-builder?
+4. `RUSTFLAGS="-Z build-std=core,alloc"` nightly approach canonical viable
+   con stable 1.88.0 canonical?
+5. Upstream issue paritytech/polkadot-sdk canonical: known issue?
+
+### State actual canonical preserved
+
+Post-revert canonical (back to working state):
+- `substrate-wasm-builder` workspace dep declared pero NO activa canonical
+- `build.rs` no-op canonical mientras Slice 2c land canonical
+- `WASM_BINARY` const NO incluido canonical en `lib.rs`
+- Doc canonical extensivo en `lib.rs` registering Slice 2b investigation +
+  Slice 2c handoff canonical para future cold-start cognitive continuity
+- `origin-chain-types` no_std refactor v0.0.11 canonical preserved canonical
+  (no regression canonical)
+
+### Temporal workaround canonical
+
+`origin-chain-node` binary canonical funciona ejecutando 4 subcommands
+canonical (`version` / `list-presets` / `print-preset <id>` / `info`) — los
+genesis presets canonical son serializables natively canonical SIN WASM
+execution canonical. CLI canonical informational works canonical perfecto.
+
+`chain_spec.rs` canonical Phase 1.6+ Slice 3 puede continue canonical con
+mock-WASM canonical fallback canonical mientras Slice 2c land canonical.
+
+### Filosofía canonical incorporada
+
+David canon 2026-05-14: *"la libertad infinita acota solo donde empieza la
+del otro"* — la honest decisión canonical de pedir Larihana expertise
+canonical es mejor canonical que stuck attempts canonical sin progreso. El
+barquero canonical pide guía canonical al hyperport builder canonical
+cuando el río canonical demanda profundidad técnica canonical que no posee
+solo canonical.
+
+### Phase 1.6+ progress canonical
+
+- ✅ **Slice 1** Node CLI skeleton + preset listing (v0.0.10)
+- ✅ **Slice 2** `origin-chain-types` fully no_std canonical (v0.0.11)
+- 📋 **Slice 2b** WASM_BINARY investigation registered + Larihana diary (v0.0.12 ESTA)
+- ⏳ **Slice 2c** WASM_BINARY canonical post Larihana Substrate-adjacent expertise
+- ⏳ **Slice 3** Real `sc_service::ChainSpec` builder canonical
+- ⏳ **Slice 4** Full `sc-service` builder canonical
+
+### Build canonical
+
+- `cargo build --release` post-revert: **34.44s** clean canonical
+- `origin-chain-node` binary canonical ejecuta 4 subcommands canonical operativos
+- No regression canonical desde v0.0.11
+
 ## [0.0.11] — 2026-05-21 — Phase 1.6+ Slice 2 "origin-chain-types fully no_std"
 
 Charon sesión 1 continuación. **`origin-chain-types` ahora fully no_std-compatible