feat(emission): FIX-6 Stage 1 — emision que paga validadores (V2-CA2) + remover APR falso

Build + tests verde: emission pallet 5 + runtime 28 (incl. emission_pallet_index_13)
+ staking contract 4. Verificacion adversarial ultracode (2 skeptics): correctitud
+ seguridad CONFIRMADAS (split exacto, sin overflow, autor solo-desde-Aura sin
input de usuario, mint-None-seguro, sin dispatchable explotable, APR removal
honesto). 'partial' solo por cobertura de tests en ramas triviales (None /
reward==0), NO por vulnerabilidad.

Cierra V2-CA2 (la cadena no tenia emision -> los validadores ganaban 0 OGC):

NUEVO pallet origin-chain-emission (Index 13):
- on_initialize cada bloque: identifica al autor Aura (FindAuthor =
  pallet_session::FindAccountFromAuthorIndex<Runtime, Aura>), mintea un
  BlockReward (10 OGC, ~5.26% inflacion anual) y lo reparte:
  - 70% al autor (el validador que produjo el bloque).
  - 20% al treasury (og/gvtry — la MISMA cuenta-vault de governance FIX-6).
  - 10% al subsidy pool (og/subsy — proof-of-equity que financia el subsidio
    de hardware anti-clasista #16).
- El residual del split va al subsidy (no pierde unidades por redondeo de bps).
- TotalEmitted trackea la inflacion acumulada on-chain. mint_into (fungible::
  Mutate) = emision real (aumenta total issuance).
- El autor viene SOLO de FindAuthor/Aura (no de input de usuario) -> nadie puede
  mintear a una cuenta arbitraria. Si FindAuthor devuelve None, no mintea. Sin
  overflow (saturating_mul/div, 10^19 << u128::MAX).

sub_mult ORTOGONAL (David 2026-06-10): el subsidy pool financia el subsidio de
hardware SIN importar la suscripcion premium. Esta emision lo alimenta; el
OnChargeTransaction de Stage 2 lo consumira.

Remover APR falso (V1/V2 fake APR): staking contract default_chn3 reward rates
8/5/3% -> 0. Era enganoso (no habia motor que los pagara; los campos
reward_rate_bps se almacenaban pero NUNCA se leian, rewards_accumulated jamas se
acreditaba). Los validadores ahora cobran via la emision real; las tasas de
staking reales las define Stage 2 (NPoS por stake).

FIX-6 Stage 1 COMPLETO (con v0.0.56 treasury real): emision + treasury real +
APR removido. Stage 2: NPoS (pallet_staking + EraPayout) + fee unificado
(OnChargeTransaction con sub_mult ortogonal).

FOLLOW-UPS (low, documentados): anadir tests de cobertura para las ramas
FindAuthor==None (no mintea) y reward==0 (requieren un 2o mock runtime);
BlockReward fijo (decay schedule = Stage 2); el subsidy pool acumula pero no se
consume hasta el OnChargeTransaction de Stage 2; genesis mainnet del treasury
vault (pre-launch).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "crates/origin-chain-agent-identity",
     "crates/origin-chain-bridges",
     "crates/origin-chain-governance",
+    "crates/origin-chain-emission",
     "crates/origin-chain-runtime",
     "crates/origin-chain-node",
 ]
@@ -201,6 +202,7 @@ origin-chain-fees = { path = "crates/origin-chain-fees", version = "0.0.1", defa
 origin-chain-agent-identity = { path = "crates/origin-chain-agent-identity", version = "0.0.1", default-features = false }
 origin-chain-bridges = { path = "crates/origin-chain-bridges", version = "0.0.1", default-features = false }
 origin-chain-governance = { path = "crates/origin-chain-governance", version = "0.0.1", default-features = false }
+origin-chain-emission = { path = "crates/origin-chain-emission", version = "0.0.1", default-features = false }
 origin-chain-runtime = { path = "crates/origin-chain-runtime", version = "0.0.1", default-features = false }
 origin-chain-node = { path = "crates/origin-chain-node", version = "0.0.1" }