feat(portfolio): wire SKH01-V2-DD sleeve @25% effective -> 4-sleeve book

Add Skyhook (SKH01_V2_DD) as a portfolio sleeve. Effective weight 25%: the three
existing sleeves scaled into the remaining 0.75 keeping their 55:25:20 ratio
(TP01 41.25% / XS01 18.75% / VRP01 15% / SKH01 25%).

_skyhook_returns(): 50/50 BTC+ETH daily series of the dual-TF regime+breakout engine
(causal, net 0.10% RT), same convention as the marginal lens.

Portfolio impact (run_portfolio.py), 3-sleeve -> 4-sleeve:
  FULL Sharpe 1.68 -> 2.13 (+0.45), FULL maxDD 14.3% -> 7.8% (halved)
  HOLD-OUT Sharpe 1.63 -> 2.30 (+0.67), HOLD-OUT maxDD ~3.5% (flat)
  Positive every year 2019-26 (annual DD <=7.8%) vs buy&hold 50/50 FULL Sh 0.93 / DD 76%.

Skyhook is quasi-orthogonal (corr ~0.09 to TP01) so it lifts Sharpe AND cuts DD.
Research portfolio (fixed weights, no real rebalancing cost at $600; Skyhook daily
Sharpe is the step-marked lens convention) -> forward-monitor, not deploy.
Tests: 25 pass (skyhook 8 + portfolio 7 + vrp 4 + trend 6). Diary + CLAUDE.md updated.

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

CLAUDE.md

@@ -51,11 +51,23 @@ Prima ondata di ricerca onesta su BTC/ETH certificati (5 track, harness condivis
   monitor forward. NB il gate concentra XS nei regimi dispersi (2025-26 = hold-out alta-dispersione).
   Ricerca `scripts/portfolio/{xsec_research,xsec_blend,xsec_dispgate}.py`. Diari `2026-06-19-hyperliquid-xsec`
   / `-xsec-blend` / `-xsec-dispgate` / `-xsec-universe-expansion` / `-trend-multiasset`.
-- **PORTAFOGLIO ATTIVO = TP01 (55%) + XS01 (25%) + VRP01 (20%)** (`src/portfolio/sleeves.active_sleeves`):
+- **PORTAFOGLIO ATTIVO = TP01 (41.25%) + XS01 (18.75%) + VRP01 (15%) + SKH01 (25%)** (`src/portfolio/sleeves.active_sleeves`):
   TP01+XS01 combinato **FULL Sharpe 1.55, HOLD-OUT 1.55, DD 4.4%**. Aggiunto **VRP01** (options
   short-vol, sotto): TP01+VRP01 da solo fa FULL Sh 1.30→1.44 / HOLD 0.31→0.40 a peso 20% (3-way da
-  validare locale con dati HL). Report `scripts/portfolio/run_portfolio.py`. Sleeve a date d'inizio
-  diverse → outer-join con pesi rinormalizzati (TP01 da solo 2019-20, VRP dal 2021, blend pieno dal 2024).
+  validare locale con dati HL). **Aggiunto SKH01-V2-DD @25% effettivo (2026-06-23, sotto):** i tre
+  preesistenti scalati nel restante 0.75 (rapporto 55:25:20). Il portafoglio a **4 sleeve** fa
+  **FULL Sharpe 1.68→2.13, HOLD-OUT 1.63→2.30, DD full 14.3%→7.8%** (Skyhook è quasi-ortogonale,
+  corr ~0.09). Report `scripts/portfolio/run_portfolio.py`. Sleeve a date d'inizio
+  diverse → outer-join con pesi rinormalizzati (TP01/SKH01 dal 2019, VRP dal 2021, XS dal 2024).
+- **SKH01-V2-DD "Skyhook" — DIVERSIFICATORE quasi-ortogonale (research)** — `src/strategies/skyhook.SKH01_V2_DD`,
+  sleeve `src/portfolio/sleeves._skyhook_returns`. Sistema dual-TF (segnale 690m / exec 230m) regime
+  (BuzVola/BuzVolume tipo-Chande) AND pattern (Donchian breakout), NON trend-follower, L/S. Vincitrice
+  di 2 onde multi-agente (la 2ª = DD-reduction): exit a **percentuale fissa ASIMMETRICA** (long sl4%/tp10%,
+  short sl2%/tp8% più stretto) → standalone **maxDD BTC 21% / ETH 27% (<30%)**, minFull +0.99, minHold
+  +1.26, causale (0/400), fee-surviving 0.40%RT. Marginal vs TP01 **ADDS** (corr 0.09, has_insample_edge,
+  robust_oos multicut 7/7, is_hedge=False); blend 0.75·TP01+0.25·SKH **hold-out 0.31→1.17**. Verificato
+  leak-free + 2 scettici. **CAVEAT:** equity daily-step (Sharpe lens), ETH DD margine sottile, book 230m
+  (costi ribilanciamento da verificare a deploy) → research win, forward-monitor. Diario `2026-06-23-skyhook.md`.
 - **VRP01 Options Short-Vol — DIVERSIFICATORE da FinanceOld/OptionsAgent** — `src/portfolio/sleeves._vrp_combo_returns`.
   Put credit spread settimanale (vendi put -0.28, compra put -0.10) gated su IV-rank. Idee portate da
   `../FinanceOld/OptionsAgent` (Bear Call Spread + gate d'ingresso). Migliora il lead VRP nudo