feat: add full derivatives analytics layer (options + futures)

Implements all phases of the derivatives expansion plan:

Rust core (crates/ferro_ta_core/src/options/, src/futures/):
- BSM and Black-76 pricing (scalar + vectorized batch)
- Greeks: delta, gamma, vega, theta, rho
- Implied volatility solver (Newton + bisection fallback)
- Smile/skew metrics: ATM IV, 25-delta RR/BF, skew slope, convexity
- Chain helpers: moneyness labels, strike selection by offset or delta
- Synthetic forwards, basis, annualized basis, implied carry, carry spread
- Continuous contract stitching: weighted, back-adjusted, ratio-adjusted
- Curve analytics: calendar spreads, slope, contango/backwardation summary

PyO3 bindings (src/options/, src/futures/):
- All Rust functions registered and exposed via _ferro_ta extension

Python API (python/ferro_ta/analysis/):
- options.py: pricing, greeks, IV, smile, chain, legacy iv_rank/percentile/zscore
- futures.py: basis, carry, curve, roll, synthetic, continuous contracts
- options_strategy.py: typed strategy schemas (expiry/strike selectors, leg presets, risk controls, simulation limits)
- derivatives_payoff.py: multi-leg payoff aggregation and Greeks aggregation

Bug fix: wrap _to_f64 calls in iv_rank/iv_percentile/iv_zscore to raise
FerroTAInputError (not plain ValueError) for 2D array input.

Docs: derivatives.rst, derivatives-analytics.md, options-volatility.md,
quickstart.rst, index.rst, api/analysis.rst all updated.

Tests: 2053 pass, 12 skipped. All CI checks pass locally.

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

tests/unit/test_data_pipeline.py

@@ -622,9 +622,15 @@ class TestComputeMany:
             close=close,
         )
 
-        np.testing.assert_allclose(results[0], SMA(close, timeperiod=10), equal_nan=True)
-        np.testing.assert_allclose(results[1], EMA(close, timeperiod=12), equal_nan=True)
-        np.testing.assert_allclose(results[2], RSI(close, timeperiod=14), equal_nan=True)
+        np.testing.assert_allclose(
+            results[0], SMA(close, timeperiod=10), equal_nan=True
+        )
+        np.testing.assert_allclose(
+            results[1], EMA(close, timeperiod=12), equal_nan=True
+        )
+        np.testing.assert_allclose(
+            results[2], RSI(close, timeperiod=14), equal_nan=True
+        )
 
     def test_hlc_indicators_match_public_api(self):
         from ferro_ta import ADX, ATR
@@ -653,7 +659,9 @@ class TestComputeMany:
         from ferro_ta.data.batch import compute_many
 
         _, _, _, close, _ = _make_ohlcv(80)
-        result = compute_many([("STDDEV", {"timeperiod": 10, "nbdev": 2.0})], close=close)
+        result = compute_many(
+            [("STDDEV", {"timeperiod": 10, "nbdev": 2.0})], close=close
+        )
         np.testing.assert_allclose(
             result[0], STDDEV(close, timeperiod=10, nbdev=2.0), equal_nan=True
         )