keep the phone credit line on screen

On phones the credit line kept white-space: nowrap, so map plus outline credits ran past the right edge and cut off the Data attribution link. Cesium's credit block is absolutely positioned inside #cesium-credits, so the box needs a real width for the credits to wrap: give it the screen width divided by its 0.8 scale, overriding the dock's width: auto !important the way the phone offset already does. Desktop keeps its one-line rule.

changelog.d/842-voice-outlines.md

@@ -30,3 +30,6 @@
 - Skip Nominatim place and outline lookups when the server reports that no
   Nominatim endpoint is configured, so a default install sends no request it
   would refuse (Manjunath, #842).
+- Keep the phone credit line on screen when map and outline credits make it
+  longer, wrapping it within the screen instead of running off the edge
+  (Manjunath, #842).