Maps in widened views: TAB overlay in place, M map across the full width

- hud: shift SetViewport/Clear with moved windows (TAB overview map)
- megamap: view constants patched to the render width (clip, scroll limit,
  edge scrolling, centre, dark band, zoomed view and its markers); frame
  stretched to the screen edges, zoom controls and their click area centred
- hud: Anchor::Screen windows are drawn and clicked unshifted but still own
  the event scope
- autotest waits for log markers instead of fixed delays (~18 s per run)

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

src/mods/megamap.h

@@ -0,0 +1,9 @@
+#pragma once
+
+namespace mods::megamap {
+
+// Sets the large map's view constants to the render width (once, when the
+// render size is applied).
+void PatchLayout(int width);
+
+} // namespace mods::megamap