feat: add finite lifetimes and despawn mechanics for rotten and cursed apples

include/consts.h

@@ -8,6 +8,12 @@ const int START_LENGTH_HARD = 2;
 const int APPLE_SCORE = 10;
 const int CURSE_DURATION_TICKS = 40;
 
+// Evil item lifetimes (in game ticks, so density stays balanced across speed scaling)
+const int BAD_APPLE_LIFETIME_TICKS    = 80; // Rotten apple lasts 80 ticks (~8 spawn cycles)
+const int CURSED_APPLE_LIFETIME_TICKS = 90; // Cursed apple lasts 90 ticks before despawning
+const int EVIL_ITEM_BLINK_TICKS       = 20; // Last 20 ticks: flashes to warn player of imminent despawn
+const int EVIL_ITEM_FAST_BLINK_TICKS  = 8;  // Last 8 ticks: rapid strobe before disappearing
+
 // Cursed apple palette indices in SPRITE_PALETTE_SUB
 const uint16_t CURSE_PAL_OUTLINE = 16;
 const uint16_t CURSE_PAL_FILL    = 17;