fix(D2-W2): correct manual-lane exemption, drop read-only item C_LANEPLAYS write

isOnManualLane predicate now correctly treats unnamed fixed-lane lanes as manual;
item-side C_LANEPLAYS loop removed (SDK read-only); explicit #include <set> in
view_mode_model.cpp; undo-block omission in detectNewContent documented as intentional.

src/view_mode_model.cpp

@@ -6,6 +6,7 @@
 #include <climits>
 #include <cstdio>
 #include <cstdlib>
+#include <set>
 #include <utility>
 
 // view_mode_model implementation.