Add out of bounds fetching

server/config.py

@@ -12,6 +12,10 @@ from pipeline.config import (
     DEFAULT_MAX_PRICE,
 )
 
+# Extra area to return beyond requested bounds (0.2 = 20%)
+# Makes panning smoother by preloading nearby hexagons
+BOUNDS_BUFFER_PERCENT = 0.2
+
 __all__ = [
     "AGGREGATES_DIR",
     "VALID_RESOLUTIONS",
@@ -22,4 +26,5 @@ __all__ = [
     "DEFAULT_MAX_YEAR",
     "DEFAULT_MIN_PRICE",
     "DEFAULT_MAX_PRICE",
+    "BOUNDS_BUFFER_PERCENT",
 ]