Add exit-confirm modal (fullscreen dim, centered P2 text) and keyboard shortcuts

Add an in-game exit confirmation modal for Playing state: ESC opens modal and pauses the game; YES resets and returns to Menu; NO hides modal and resumes.
Draw a full-window translucent dim background (reset viewport) so overlay covers any window size / fullscreen.
Use PressStart2P (pixel P2) font for all modal text and center title/body/button labels using measured text widths.
Add FontAtlas::measure(...) to accurately measure text sizes (used for proper centering).
Ensure popup rendering and mouse hit-testing use the same logical/content-local coordinate math so visuals and clicks align.
Add keyboard shortcuts for modal (Enter = confirm, Esc = cancel) and suppress other gameplay input while modal is active.
Add helper scripts for debug build+run: build-debug-and-run.ps1 and build-debug-and-run.bat.
Minor fixes to related rendering & state wiring; verified Debug build completes and modal behavior in runtime.

src/states/State.h

@@ -12,6 +12,10 @@ class Starfield3D;
 class FontAtlas;
 class LineEffect;
 
+// Forward declare StateManager so StateContext can hold a pointer without
+// including the StateManager header here.
+class StateManager;
+
 // Shared context passed to states so they can access common resources
 struct StateContext {
     // Core subsystems (may be null if not available)
@@ -41,6 +45,9 @@ struct StateContext {
     // Menu popups (exposed from main)
     bool* showLevelPopup = nullptr;
     bool* showSettingsPopup = nullptr;
+    bool* showExitConfirmPopup = nullptr; // If true, show "Exit game?" confirmation while playing
+    // Pointer to the application's StateManager so states can request transitions
+    StateManager* stateManager = nullptr;
 };
 
 class State {