Unify input behind Engine::Input facade; fix Ctrl+P and Pause button

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).

App/scripts/WASDMove.cpp

@@ -12,15 +12,16 @@
 
 #include <Engine/Scripting/Script.h>
 #include <Engine/Core/Application.h>
-#include <Engine/Core/Window.h>
+#include <Engine/Core/Input.h>
 #include <Engine/Renderer/Renderer.h>
 #include <Engine/Renderer/EditorCamera.h>
 #include <Engine/Physics/PhysicsWorld.h>
 
-#include <GLFW/glfw3.h>
 #include <glm/glm.hpp>
 #include <glm/gtc/quaternion.hpp>
 
+using namespace Engine;   // Input 门面（统一输入入口）
+
 namespace {
 
     class WASDMove final : public Engine::Scripting::ScriptBehavior {
@@ -29,7 +30,8 @@ namespace {
 
         void OnUpdate(float dt) override {
             // 位移方向 = 视线水平投影（W 前进 / A 左 / D 右），UE Scene
-            // view 移动惯例；Y 锁 0（升降/跳跃归物理或将来扩展）
+            // view 移动惯例；Y 锁 0（升降/跳跃归物理或将来扩展）。
+            // 键鼠查询统一走 Input 门面（脚本层零 GLFW 依赖）
             const glm::quat cq = App().GetRenderer()
                                      .GetEditorCamera()
                                      .GetTransform()
@@ -37,12 +39,11 @@ namespace {
             const glm::vec3 fwd = cq * glm::vec3(0.0f, 0.0f, -1.0f);
             const glm::vec3 right = cq * glm::vec3(1.0f, 0.0f, 0.0f);
 
-            auto& win = App().GetWindow();
             glm::vec3 move(0.0f);
-            if (win.IsKeyPressed(GLFW_KEY_W)) move += fwd;
-            if (win.IsKeyPressed(GLFW_KEY_S)) move -= fwd;
-            if (win.IsKeyPressed(GLFW_KEY_D)) move += right;
-            if (win.IsKeyPressed(GLFW_KEY_A)) move -= right;
+            if (Input::IsKeyDown(Input::Key::W)) move += fwd;
+            if (Input::IsKeyDown(Input::Key::S)) move -= fwd;
+            if (Input::IsKeyDown(Input::Key::D)) move += right;
+            if (Input::IsKeyDown(Input::Key::A)) move -= right;
             move.y = 0.0f;
             if (glm::length(move) > 1e-4f) {
                 move = glm::normalize(move);