fix: speed limit rounding, controlsd crashes, modeld calibration rate

- Speed limit display uses round() instead of floor() to fix off-by-one
- Initialize driving_gear in controlsd __init__ to prevent AttributeError
- Fix gpsLocation capnp access (attribute style, not getter methods)
- Fix sm.valid dict access (brackets not parentheses)
- modeld runs full 20fps during calibration instead of throttled 4fps
- Over-speed warning threshold below 50mph changed from 5 to 7

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

selfdrive/clearpilot/speed_logic.py

@@ -43,7 +43,7 @@ class SpeedState:
       unit = "mph"
 
     speed_int = int(math.floor(speed_display))
-    speed_limit_int = int(math.floor(speed_limit_display))
+    speed_limit_int = int(round(speed_limit_display))
     cruise_int = int(round(cruise_display))
 
     self.prev_speed_limit = speed_limit_int
@@ -61,7 +61,7 @@ class SpeedState:
     cruise_engaged = cruise_active and not cruise_standstill
 
     if speed_limit_int >= 20 and cruise_engaged and cruise_int > 0:
-      over_threshold = 10 if speed_limit_int >= 50 else 5
+      over_threshold = 10 if speed_limit_int >= 50 else 7
       if cruise_int >= speed_limit_int + over_threshold:
         warning = "over"
         warning_speed = str(cruise_int)