GUI: allow movement while open; freeze look and block bind capture

Feedback pass on the preview shell:

- Freeze the rendered view explicitly in CreateMove and again at
  FRAME_RENDER_START; CInput was still letting mouse look move the camera.
- Allow normal WASD/jump/duck movement while the GUI is open; strip
  attack/use/impulse/weapon selection so GUI clicks do not fire.
- While bind capture is active, block all game input.
- Esc no longer closes the GUI; it only cancels bind capture. F2 or the
  title-bar X close the preview.
- Interpose SDL_ShowCursor / SDL_SetRelativeMouseMode / warp / window grab so
  the game cannot re-capture or hide the native cursor while the GUI is open.

1 files changed, 3 insertions, 2 deletions

diff --git a/docs/adr/0001-custom-isurface-gui.md b/docs/adr/0001-custom-isurface-gui.md
index 9da3c0c..9595ca8 100644
--- a/docs/adr/0001-custom-isurface-gui.md
+++ b/docs/adr/0001-custom-isurface-gui.md
@@ -38,8 +38,9 @@ path.
 - Left sidebar categories (Movement, Combat, Visuals, Weapons, System) and a
   content pane of feature cards with collapsible settings.
 - Native OS cursor by releasing SDL relative-mouse mode while the GUI is open.
-- While open, freeze usercmd input/view and skip combat features; keep the
-  game simulating and keep ESP/FOV circle/speed graph drawing.
+- While open, freeze look/attack/use and skip combat features, but allow
+  normal movement; bind capture blocks all game input. Keep the game
+  simulating and keep ESP/FOV circle/speed graph drawing.
 - Replace the text menu with the GUI. No permanent fallback menu; git history
   retains the old implementation.