fix(gun_harness): bump virtual bullet ring buffer 512→2048

With 12 guns × 4 power bins = 48 bullets/tick, 512 slots overflow
before slow bullets resolve (~36 ticks travel). 2048 gives headroom.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

common_libs/gun_harness/virtual_bullets.nim

@@ -9,7 +9,7 @@ import gun_interface
 const
   PowerBins*    = [1.0, 1.5, 2.0, 3.0]  ## 4 bins; ponytail: fixed array, add runtime config if needed
   WindowSize*   = 50                      ## rolling window ticks for fitness
-  MaxBullets*   = 512                     ## hard cap; ponytail: ring buffer, resize if more guns added
+  MaxBullets*   = 2048                    ## hard cap; ponytail: ring buffer, resize if more guns added
   MinHitRate*   = 0.40                    ## 40% threshold for acceptable power selection
 
 type

test_displacement_battles.nim

@@ -0,0 +1,27 @@
+import std/[os, strformat]
+import common_libs/test_framework/test_framework
+
+const
+  modularBotDir  = "/home/davide/Projects/SirRoboGarage/ModularBot_garage"
+  samplesDir     = "/home/davide/Downloads/robocode-tankroyale/sample-bots-nim-linux-1.0.7"
+  crazy          = samplesDir / "Crazy"
+  waveSurfer     = "/home/davide/Projects/SirRoboGarage/WaveSurfer_garage"
+  patternMover   = "/home/davide/Projects/SirRoboGarage/PatternMover_garage"
+
+const serverJar = "/home/davide/Projects/tank-royale/server/build/libs/robocode-tankroyale-server-0.35.5-all.jar"
+const runnerJar = "/home/davide/Projects/tank-royale/runner/examples/lib/robocode-tankroyale-runner.jar"
+
+if not fileExists(serverJar) or not fileExists(runnerJar):
+  echo "Skipping: Tank Royale JARs not found"
+  quit(0)
+
+proc battle(name: string, dir: string) =
+  echo fmt"--- ModularBot vs {name} (10 rounds) ---"
+  let r = runBattle(@[modularBotDir, dir], rounds = 10, timeout = 300000, maxSpeed = true)
+  for result in r.results:
+    echo fmt"  {result.name}: score={result.totalScore} rank={result.rank}"
+  echo ""
+
+battle("Crazy",        crazy)
+battle("WaveSurfer",   waveSurfer)
+battle("PatternMover", patternMover)