WASD: resume the walk right after a weapon set switch (untested in-game)

Switching between weapon classes resets the hero's animation state inside
cUI_Taskbar2::SelectWeaponSet, which dropped the walk for a tick. The hook
sends the WASD walk again at once. Checkpoint before the movement rework.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/mods/wasd.h

@@ -5,4 +5,8 @@ namespace mods::wasd {
 // Whether `vk` is one of the movement keys W/A/S/D.
 bool IsMovementKey(int vk);
 
+// Sends the walk for the held movement keys now, after something stopped the
+// hero mid-walk (a weapon set switch).
+void ResumeWalk();
+
 } // namespace mods::wasd