show threat budget in debug text overlay

src/lib/sim/Simulation.cpp

@@ -555,6 +555,11 @@ Tick Simulation::bossCountdownTicks() const
     return m_waveSystem->bossCountdownTicks();
 }
 
+Tick Simulation::normalGapRemainingTicks() const
+{
+    return m_waveSystem->normalGapRemainingTicks();
+}
+
 int Simulation::schematicLevel(const std::string& shipId) const
 {
     const std::map<std::string, SchematicState>::const_iterator it =

src/lib/sim/Simulation.h

@@ -59,7 +59,8 @@ public:
     bool   isGameOver()           const;
     double threatLevel()          const;
     int    bossWaveCounter()      const;
-    Tick   bossCountdownTicks()   const;
+    Tick   bossCountdownTicks()         const;
+    Tick   normalGapRemainingTicks()    const;
 
     // Schematic state queries.
     int  schematicLevel(const std::string& shipId)    const;

src/lib/sim/WaveSystem.cpp

@@ -113,6 +113,11 @@ Tick WaveSystem::bossCountdownTicks() const
     return m_bossCountdownTicks;
 }
 
+Tick WaveSystem::normalGapRemainingTicks() const
+{
+    return m_normalGapRemainingTicks;
+}
+
 // ---------------------------------------------------------------------------
 // Private helpers
 // ---------------------------------------------------------------------------

src/lib/sim/WaveSystem.h

@@ -46,6 +46,10 @@ public:
     // Ticks remaining until the next boss wave fires (REQ-WAV-BOSS-COUNTDOWN).
     Tick bossCountdownTicks() const;
 
+    // Ticks remaining on the current normal-wave gap timer (REQ-WAV-GAP).
+    // Frozen during quiet windows.
+    Tick normalGapRemainingTicks() const;
+
 private:
     struct SpawnEntry
     {