feat(portfolio): Deribit-only executable book (TP01+SKH01) + periodic rebalancing

- deribit_book_sleeves(): TP01 75% + SKH01 25% — the two directional BTC/ETH legs on
  ONE venue (Deribit), both since 2019. Excludes XS01 (Hyperliquid/stat-mode) & VRP01
  (modeled options). FULL Sharpe 1.78 / HOLD 1.17 / DD 9.4% (research).
- rebalance_sim(): realistic PERIODIC rebalancing (drift between dates, turnover cost at
  Deribit-taker ~5bps/side) vs the idealized continuous rebalance of combined_daily.
  period=1 + cost=0 reduces to continuous (tested).
- run_deribit_book.py: report — continuous vs weekly/biweekly/monthly rebal, per-year,
  accumulation €2k & $600-real, min-order $5 note. Finding: turnover is LOW (0.2-0.4x/yr),
  so monthly rebal (€7,919) ~= continuous (€7,938) — cost is negligible; daily would be
  sub-min-order fiction at $600 -> use >= weekly.
- +2 tests (rebalance_sim continuity & cost). Full suite green.

TP01 is the only live-armed leg; SKH01 is the candidate 2nd leg (validate execution code first).

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

src/portfolio/sleeves.py

@@ -253,3 +253,16 @@ def active_sleeves() -> list[Sleeve]:
         vrp_sleeve(weight=0.15),       # options short-vol (put credit spread + gate IV-rank), dal 2021 (lead modellato, scorrelato)
         skyhook_sleeve(weight=0.25),   # dual-TF regime+breakout BTC/ETH, dal 2019 (quasi-ortogonale, exit %-asimmetrici, research)
     ]
+
+
+def deribit_book_sleeves() -> list[Sleeve]:
+    """BOOK DERIBIT-ONLY realmente eseguibile (TP01 + SKH01, 75/25): le DUE gambe direzionali
+    BTC/ETH sullo stesso venue (Deribit), entrambe dal 2019. Esclude XS01 (Hyperliquid, stat-mode)
+    e VRP01 (opzioni modellate). FULL Sharpe ~1.78 / HOLD ~1.17 / DD ~9% (research; SKH01 daily-step).
+    Pensato per il deploy reale a basso capitale: stesso conto, stesso feed, ribilanciamento
+    periodico (vedi src.portfolio.portfolio.rebalance_sim + scripts/portfolio/run_deribit_book.py).
+    TP01 e' gia' armato live; SKH01 e' il candidato 2a gamba (da validare codice d'esecuzione)."""
+    return [
+        tp01_sleeve(weight=0.75),
+        skyhook_sleeve(weight=0.25),
+    ]