New Engine/Core/Input.h/.cpp: static input facade with a Key/MouseButton
enum (values map to GLFW key codes internally) so scripts and game logic
no longer touch GLFW directly - window backend becomes swappable and the
facade is the surface to expose when embedding scripting later. Wired up
in Application's constructor; Camera (editor camera WASD/RMB/MMB), the
WASDMove script and SandboxApp key handling now query Input only.
Ctrl+P hotkey fix: the !m_Playing guard made the hotkey dead exactly
when it was needed - after pressing Play. Now toggles both ways.
Toolbar Pause button now reads "Resume" while paused (tooltip follows).
Clearer accessor naming on ScriptBehavior (Get -> GetComponent,
TryGet -> TryGetComponent), WASDMove follows. Teleport marked const
(JPH Ref does not propagate constness). Spinner: auto-rotation
disabled for the moment, registration switched from the registration
macro to an explicit lambda to verify the mechanism.
ScriptBehavior gains App() host access (Application injected via
ScriptRuntime), TryGet<T> and EntityBits for physics facade addressing.
WASDMove maps WASD to the editor camera's horizontal heading (UE
gameplay convention): dynamic bodies go through the physics velocity
facade preserving the vertical component (zeroing Y would cancel
gravity mid-fall), bodiless entities translate their transform directly.
Editor-mode key conflict is naturally avoided: RMB-held flight consumes
WASD, release hands keys to the script.