Fix all audit issues: survival check performance, display consistency, atomic config write, credential validation, TP null handling, highest_open preservation, stale docstring

state.py

@@ -106,10 +106,16 @@ class BotState:
         ) / 2.0
 
         # Highest open position entry price
+        # When no positions are open, keep the last known value rather than
+        # falling back to current price — this prevents the grid floor from
+        # collapsing to current_price * 0.40 after all positions close.
         open_prices = [pos_level(p) for p in positions]
-        self.highest_open_price = (
-            max(open_prices) if open_prices else self.current_price
-        )
+        if open_prices:
+            self.highest_open_price = max(open_prices)
+        elif self.highest_open_price == 0.0:
+            # First run with no positions — use current price as seed
+            self.highest_open_price = self.current_price
+        # else: keep existing highest_open_price from previous loop
 
         # Lowest level across all positions and orders
         order_prices = [ord_level(o) for o in orders]