feat(consensus): Phase 1.4 — Consensus PoA canonical Aura+GRANDPA v0.0.6

Origin Chain runtime canonical ahora produces blocks + finalizes via
Aura+GRANDPA per CHN-1 ratified. PoA Phase 1 substrate fundación bien anclada.

## Pallets añadidos canonical (per SBS-4)

- Index 4 Aura (pallet_aura 39.0.0) — block production canonical PoA per CHN-1
  Round-Robin 6-segundo slots alineados Pi 5 + NVMe SSD. AuraId sr25519.
- Index 5 Grandpa (pallet_grandpa 40.0.0) — finality gadget per CHN-1
  2/3 honest majority irreversible confirmation. GrandpaId Ed25519.

## Primitives consumidas
- sp-consensus-aura 0.42.0 (feature serde canonical)
- sp-consensus-grandpa 23.0.0 → 23.1.0 (feature serde canonical)

## Configs canonical
- pallet_aura::Config: MaxAuthorities 32 + AllowMultipleBlocksPerSlot false
  + SlotDuration = MinimumPeriodTimesTwo (clock↔consensus coupling canonical)
- pallet_grandpa::Config: MaxAuthorities 32 + MaxNominators 0 + KeyOwnerProof
  Void + EquivocationReportSystem () (Phase 1 simple, real Phase 2 NPoS)

## Wiring canonical clock↔consensus
pallet_timestamp::OnTimestampSet = crate::Aura (was ()) — cada nuevo
timestamp triggera Aura slot advance canonical. Materializa 6-segundo block
production deterministic Pi 5.

## Opaque SessionKeys canonical (nuevo opaque.rs module)
impl_opaque_keys! con aura (sr25519) + grandpa (Ed25519) — substrate canonical
pattern para forkless runtime upgrades. Cada validator posee 2 keys canonical.
Pre-Phase 1.5: static keys en genesis chain_spec. Phase 1.5: pallet_session
introduces rotation 4h epochs per CHN-1.

## Filosofía canonical
opaque.rs cita David canon 2026-05-14 "la libertad infinita acota solo donde
empieza la del otro" — opaque types son la frontera canonical entre node
sovereignty + runtime sovereignty. Each layer respeta la libertad del otro.

## Build + tests
- cargo check 6.17s warm cache (Aura+Grandpa deps incremental)
- cargo build --release 8.64s warm cache clean
- ~57 tests passing (count preserved — Aura/Grandpa tests llegan Phase 1.5+)

## Edge case empírico
pallet-aura 39.0.0 + pallet-grandpa 40.0.0 NO exponen feature
runtime-benchmarks en stable2512 canonical. Wire-up benchmark scaffolding
land Phase 1.5+ cuando pallet_session se integre.

## Phase 1 progress
1.1 ✅ + 1.2 ✅ + 1.3 ✅ + 1.4 ✅ (esta). Next: 1.5 pallet_session validator
rotation 4h epochs per CHN-1.

Origin Chain runtime composition canonical actual (6 pallets):
- 0 System + 1 Timestamp + 2 Balances + 3 TransactionPayment
- 4 Aura + 5 Grandpa
- Opaque SessionKeys: aura sr25519 + grandpa Ed25519

Refs: CHARON_ROADMAP_V1 Phase 1.4, CHN-1 ratified Aura+GRANDPA canonical,
SBS-4 ratified extended pallet set

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

crates/origin-chain-runtime/src/opaque.rs

@@ -0,0 +1,35 @@
+//! # Opaque types canonical — pre-genesis identification para node binary
+//!
+//! `opaque` types canonical son aquellos que el **node** consume sin necesidad
+//! de saber detalles del runtime composition. Pattern canonical Substrate: el
+//! node binary identifica session keys + block headers sin importar qué pallets
+//! exact se composen runtime-side.
+//!
+//! Esto permite **forkless runtime upgrades canonical**: el node ejecuta WASM
+//! runtime mientras los opaque types canonical permanecen wire-compatible.
+//!
+//! ## Filosofía canonical
+//!
+//! David canon 2026-05-14 *"la libertad infinita acota solo donde empieza la
+//! del otro"* — el opaque types son la frontera canonical entre node sovereignty
+//! (puede correr cualquier runtime WASM compatible) + runtime sovereignty (puede
+//! evolucionar pallets sin breakar node binaries).
+
+use crate::{AuraId, GrandpaId};
+use sp_runtime::impl_opaque_keys;
+
+impl_opaque_keys! {
+    /// Canonical session keys para Origin Chain validators canonical.
+    ///
+    /// Cada validator canonical posee:
+    /// - **`aura`**: `AuraId` (sr25519) para slot signing canonical block production
+    /// - **`grandpa`**: `GrandpaId` (Ed25519) para finality voting canonical
+    ///
+    /// Estos keys canonical se rotan periódicamente per Phase 1.5 `pallet_session`
+    /// canonical (4-hour epochs per CHN-1). Pre-Phase 1.5 = static keys canonical
+    /// definidos en genesis chain_spec.
+    pub struct SessionKeys {
+        pub aura: crate::Aura,
+        pub grandpa: crate::Grandpa,
+    }
+}