feat(autotune): apply_tuning helper for Forecast tab pre-fill

autotune.py

@@ -1,7 +1,7 @@
 import json
 import sqlite3
 from datetime import datetime, timezone
-from typing import Optional
+from typing import Optional, Tuple
 
 import numpy as np
 import pandas as pd
@@ -240,3 +240,12 @@ def run_autotune(*, predict_fn, fetch_fn, db_path: str,
     })
 
     return fig, summary, grid_df
+
+def apply_tuning(db_path: str, symbol: str, interval: str,
+                 use_tuned: bool) -> Tuple[Optional[float], Optional[float]]:
+    if not use_tuned:
+        return (None, None)
+    row = load_tuning(db_path, symbol, interval)
+    if row is None:
+        return (None, None)
+    return (float(row["best_T"]), float(row["best_top_p"]))

tests/test_autotune.py

@@ -216,3 +216,32 @@ def test_run_autotune_raises_when_all_cells_fail(tmp_db, monkeypatch):
             sample_count=1, max_anchors=5,
         )
     assert load_tuning(tmp_db, "X", "5min") is None
+
+def test_apply_tuning_returns_values_when_cached_and_enabled(tmp_db):
+    from autotune import apply_tuning
+    init_tuning_table(tmp_db)
+    save_tuning(tmp_db, "SPY", "5min",
+                {"T": 1.5, "top_p": 0.7, "total_return_pct": 7.0,
+                 "hit_rate": 0.6, "mean_rmse": 0.9},
+                [], {"lookback": 200, "pred_len": 30, "stride": 30,
+                     "sample_count": 1, "max_anchors": 20,
+                     "start_date": "", "end_date": ""})
+    t_val, top_p_val = apply_tuning(tmp_db, "SPY", "5min", True)
+    assert t_val == 1.5
+    assert top_p_val == 0.7
+
+def test_apply_tuning_returns_none_when_disabled(tmp_db):
+    from autotune import apply_tuning
+    init_tuning_table(tmp_db)
+    save_tuning(tmp_db, "SPY", "5min",
+                {"T": 1.5, "top_p": 0.7, "total_return_pct": 7.0,
+                 "hit_rate": 0.6, "mean_rmse": 0.9},
+                [], {"lookback": 200, "pred_len": 30, "stride": 30,
+                     "sample_count": 1, "max_anchors": 20,
+                     "start_date": "", "end_date": ""})
+    assert apply_tuning(tmp_db, "SPY", "5min", False) == (None, None)
+
+def test_apply_tuning_returns_none_when_no_cache(tmp_db):
+    from autotune import apply_tuning
+    init_tuning_table(tmp_db)
+    assert apply_tuning(tmp_db, "ZZZ", "1min", True) == (None, None)