🎨 Palette: Add concrete tooltip to Transaction Cost input

.Jules/palette.md

@@ -0,0 +1,3 @@
+## 2025-01-20 - Concrete Tooltips for Financial Parameters
+**Learning:** Users can find statistical and financial parameters (like bps or quantiles) ambiguous. Adding a tooltip with a concrete example (like "10 bps = 0.10%") significantly improves clarity and prevents configuration errors.
+**Action:** Always include concrete mathematical examples in tooltips for inputs that represent abstract financial units (e.g., bps, beta, quantiles).

src/dashboard.py

@@ -190,7 +190,15 @@ def get_cache_key(*args) -> str:
 
     if mode == "Single-Asset":
         st.subheader("5. Backtest Settings")
-        bt_cost = st.number_input("Transaction Cost (bps)", value=DEFAULT_COST_BPS, step=1) / 10000
+        bt_cost = (
+            st.number_input(
+                "Transaction Cost (bps)",
+                value=DEFAULT_COST_BPS,
+                step=1,
+                help="Transaction cost applied per trade (e.g., 10 bps = 0.10%).",
+            )
+            / 10000
+        )
         allow_short = st.checkbox("Allow Short Selling?", value=False)
     else:
         st.subheader("5. Alert Thresholds")