feat(npos): FIX-6 Stage 2b Paso A — pallet_staking Config cableado (infra dormida)

Materializa la infra NPoS DORMIDA del DC ORIGIN_CHAIN_NPOS_V1 (decisiones de
fundador ratificadas). pallet_staking 43.0.0 wired como Index 14: los 31
associated types cableados contra el tren stable2509-3 (mapeo quirúrgico
audit-before-claims; compiló en 2 iteraciones).

Piezas (crates/origin-chain-runtime/src/staking.rs, nuevo):
- OriginEraPayout: emisión por-era LINEAL que preserva EXACTAMENTE la tasa de
  FIX-6 Stage 1 (BlockReward 10 OGC/bloque, 70% validadores / 30% rest). NO la
  curva ideal-staking-rate de Polkadot (ignora total_staked/issuance a propósito).
- DealWithEraRemainder (RewardRemainder): reparte el rest 2/3 treasury (og/gvtry)
  + 1/3 subsidy (og/subsy) = 20%/10% del total. CRÍTICO #16: mantiene og/subsy
  alimentado bajo NPoS (sin él, el OriginFeeAdapter de Stage 2a degradaría a
  pool_covered=0 y el usuario pagaría el 100%).
- OnChainExecution<OnChainSeqPhragmen> como (Genesis)ElectionProvider (dormido:
  ForceNone no dispara elección). VoterList=UseNominatorsAndValidatorsMap +
  TargetList=UseValidatorsMap (Scores distintos, evitan bags-list + sus asserts).
- Params ratificados: MaxValidatorSet=150 (NPoS-6) · SessionsPerEra=6 (era 24h) ·
  BondingDuration=7 eras=7d (NPoS-8) · SlashDeferDuration=0 (sin slashes dormido).
- fungible::hold (NPoS-10): Currency/OldCurrency=Balances; el RuntimeHoldReason
  agregado del macro absorbe HoldReason::Staking automáticamente.

Estado: staking PRESENTE pero INERTE — SessionInterface/NextNewSession=() (no
avanza eras), genesis force_era=ForceNone sin stakers (PoA-equivalente, cero
regresión). El emission pallet Index 13 sigue siendo la fuente de emisión. NO
hay doble-emisión (staking no emite mientras no avance eras).

Pendiente (sesión fresca, encienden NPoS de verdad → verificación adversarial):
Paso B genesis poblado (invulnerables+stakers, asserts-trampa) · Paso C
SessionManager=Staking + historical (enciende EraPayout) · Paso D emission
on_initialize off (kill-switch anti-doble-emisión) · Paso E tests E2E.

spec_version 2→3 (nuevo pallet ⇒ metadata; TRANSACTION_VERSION=1 intacto).
21 suites workspace verde. cargo +1.88. WASM VPS-gated (UnknownOpcode 252).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Cargo.lock

@@ -3254,6 +3254,36 @@ dependencies = [
  "sp-crypto-hashing",
 ]
 
+[[package]]
+name = "frame-election-provider-solution-type"
+version = "16.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0b525f462fa8121c3d143ad0d876660584f160ad5baa68c57bfeeb293c6b8fb"
+dependencies = [
+ "proc-macro-crate 3.5.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
+[[package]]
+name = "frame-election-provider-support"
+version = "43.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8ddd171c606313e738594a9dabe2d2a911239e6a78b5419faf2a2d6b106570c"
+dependencies = [
+ "frame-election-provider-solution-type",
+ "frame-support",
+ "frame-system",
+ "parity-scale-codec",
+ "scale-info",
+ "sp-arithmetic",
+ "sp-core",
+ "sp-npos-elections",
+ "sp-runtime 44.0.0",
+ "sp-std",
+]
+
 [[package]]
 name = "frame-executive"
 version = "43.0.1"
@@ -6484,6 +6514,7 @@ dependencies = [
 name = "origin-chain-runtime"
 version = "0.0.1"
 dependencies = [
+ "frame-election-provider-support",
  "frame-executive",
  "frame-metadata-hash-extension",
  "frame-support",
@@ -6503,6 +6534,7 @@ dependencies = [
  "pallet-grandpa",
  "pallet-revive",
  "pallet-session",
+ "pallet-staking",
  "pallet-sudo",
  "pallet-timestamp",
  "pallet-transaction-payment",
@@ -6520,6 +6552,7 @@ dependencies = [
  "sp-offchain 39.0.0",
  "sp-runtime 44.0.0",
  "sp-session 41.0.0",
+ "sp-staking 41.0.0",
  "sp-std",
  "sp-transaction-pool 39.0.0",
  "sp-version 42.0.0",
@@ -6742,6 +6775,28 @@ dependencies = [
  "sp-trie",
 ]
 
+[[package]]
+name = "pallet-staking"
+version = "43.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2ce23099893b90f921c53ce92db08d3b9ada8ec532f3ea125e9b117236ee4808"
+dependencies = [
+ "frame-benchmarking",
+ "frame-election-provider-support",
+ "frame-support",
+ "frame-system",
+ "log",
+ "pallet-authorship",
+ "pallet-session",
+ "parity-scale-codec",
+ "scale-info",
+ "serde",
+ "sp-application-crypto 43.0.0",
+ "sp-io 43.0.0",
+ "sp-runtime 44.0.0",
+ "sp-staking 41.0.0",
+]
+
 [[package]]
 name = "pallet-sudo"
 version = "43.0.0"
@@ -11179,6 +11234,20 @@ dependencies = [
  "sp-application-crypto 42.0.0",
 ]
 
+[[package]]
+name = "sp-npos-elections"
+version = "39.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb6b7ddeb995c6d57efbc66f42c70bd513f251025fbe9de8b5903a7f87a50de7"
+dependencies = [
+ "parity-scale-codec",
+ "scale-info",
+ "serde",
+ "sp-arithmetic",
+ "sp-core",
+ "sp-runtime 44.0.0",
+]
+
 [[package]]
 name = "sp-offchain"
 version = "38.0.0"