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/editor/Editor.cpp

@@ -26,8 +26,6 @@
 #include <imgui_internal.h>   // DockBuilder*（内部 API）
 #include <ImGuizmo.h>
 
-#include <GLFW/glfw3.h>
-
 #include <filesystem>
 #include <fstream>
 
@@ -283,8 +281,9 @@ void Editor::DrawMenuBar()
 void Editor::DrawToolbar()
 {
     const ImGuiIO& io = ImGui::GetIO();
-    // Ctrl+P：文本输入中（改名/路径框）不触发，防打字误切 PIE
-    if (!m_Playing && io.KeyCtrl && !io.WantTextInput &&
+    // Ctrl+P 全局热键：编辑态进 PIE，运行态停回编辑器（双向）。
+    // 文本输入中（改名/路径框）不触发，防打字误切
+    if (io.KeyCtrl && !io.WantTextInput &&
         ImGui::IsKeyPressed(ImGuiKey_P, false))
     {
         TogglePlay();
@@ -293,12 +292,14 @@ void Editor::DrawToolbar()
     // 按钮加大触感（工具栏行高 = 一个按钮高；DockSpace avail 自适应）
     ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(12.0f, 4.0f));
     const ImGuiStyle& st = ImGui::GetStyle();
+    const char* pauseLabel = m_Paused ? "Resume" : "Pause";
 
     // Play 组宽度 → 水平居中（编辑态 1 钮 / 运行态 2 钮）
     float groupW = 0.0f;
     if (m_Playing)
     {
-        groupW = ImGui::CalcTextSize("Pause").x + ImGui::CalcTextSize("Stop").x +
+        groupW = ImGui::CalcTextSize(pauseLabel).x +
+                 ImGui::CalcTextSize("Stop").x +
                  4.0f * st.FramePadding.x + st.ItemSpacing.x;
     }
     else
@@ -309,7 +310,7 @@ void Editor::DrawToolbar()
 
     if (m_Playing)
     {
-        // Pause：暂停中亮黄常驻（UE 按下态），运行中暗黄
+        // Pause/Resume：暂停中亮黄常驻（UE 按下态），运行中暗黄
         ImGui::PushStyleColor(ImGuiCol_Button,
             m_Paused ? ImVec4(0.85f, 0.62f, 0.12f, 1.0f)
                      : ImVec4(0.55f, 0.42f, 0.10f, 1.0f));
@@ -318,7 +319,7 @@ void Editor::DrawToolbar()
                      : ImVec4(0.65f, 0.50f, 0.14f, 1.0f));
         ImGui::PushStyleColor(ImGuiCol_ButtonActive,
                               ImVec4(0.95f, 0.76f, 0.24f, 1.0f));
-        if (ImGui::Button("Pause"))
+        if (ImGui::Button(pauseLabel))
         {
             TogglePause();
         }