Re-add speed limit color mode with BRouter profile patch

The dummyUsage trick needs a separate assign per tag:
  assign dummyUsage2 = maxspeed=
(not appended to the existing smoothness= line)

- Dockerfile: Patch all BRouter profiles to include maxspeed in
  WayTags output via separate assign dummyUsage2
- brouter.ts: Extract maxspeed with direction handling
  (maxspeed:forward/backward + reversedirection awareness)
- ColoredRoute: maxspeed color mode (green ≤30, yellow ≤50,
  orange ≤70, red ≤100, dark red 100+)
- ElevationChart: maxspeed chart rendering, legend, hover "X km/h"
- PlannerMap: maxspeeds state + Yjs read + prop passing
- i18n: EN "Speed Limit" / DE "Tempolimit"
- Mock fixtures: maxspeed data for E2E tests

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

apps/planner/app/components/PlannerMap.tsx

@@ -376,6 +376,7 @@ export function PlannerMap({ yjs, onRouteRequest, highlightPosition, highlighted
   const [segmentBoundaries, setSegmentBoundaries] = useState<number[]>([]);
   const [surfaces, setSurfaces] = useState<string[]>([]);
   const [highways, setHighways] = useState<string[]>([]);
+  const [maxspeeds, setMaxspeeds] = useState<string[]>([]);
   const [colorMode, setColorMode] = useState<ColorMode>("plain");
   const [noGoDrawing, setNoGoDrawing] = useState(false);
   const toggleNoGoDraw = useCallback(() => setNoGoDrawing((v) => !v), []);
@@ -450,6 +451,13 @@ export function PlannerMap({ yjs, onRouteRequest, highlightPosition, highlighted
         setHighways([]);
       }
 
+      const maxspeedsJson = yjs.routeData.get("maxspeeds") as string | undefined;
+      if (maxspeedsJson) {
+        try { setMaxspeeds(JSON.parse(maxspeedsJson)); } catch { setMaxspeeds([]); }
+      } else {
+        setMaxspeeds([]);
+      }
+
       if (modeVal) setColorMode(modeVal);
     };
 
@@ -731,6 +739,7 @@ export function PlannerMap({ yjs, onRouteRequest, highlightPosition, highlighted
             colorMode={colorMode}
             surfaces={surfaces}
             highways={highways}
+            maxspeeds={maxspeeds}
           />
           <RouteInteraction
             coordinates={routeCoordinates}