MapView is a CWnd-derived class used across all game modes (local MP,
network, campaign, replay) for terrain/map data — not replay-specific.
Inheritance: CWnd → base (vtable 0x64C348) → MapView (vtable 0x64FC60).
Embedded in frontend dialogs as child windows for map preview/selection.
Loads .thm terrain files (current.thm for live, playback.thm for replay).
Move from engine/map_class.rs to new frontend/ module. Rename constants
(MAP_CLASS_* → MAP_VIEW_*). Update Ghidra labels.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
