Fix: Standardize MIRV travel time

Addresses player report regarding unfair and unintuitive MIRV launch delays.
MIRV travel time is now fixed at 5 ticks, independent of click location.

- Modified MIRVExecution.ts to dynamically calculate speed based on a fixed travel time.
- Added MIRVExecution.test.ts to verify the fixed travel time.

src/core/execution/MIRVExecution.ts

@@ -22,6 +22,7 @@ export class MirvExecution implements Execution {
 
   private mirvRange = 1500;
   private warheadCount = 350;
+  private MIRV_FIXED_TRAVEL_TIME = 5; // Ticks
 
   private random: PseudoRandom;
 
@@ -43,7 +44,7 @@ export class MirvExecution implements Execution {
     this.mg = mg;
     this.pathFinder = new ParabolaPathFinder(mg);
     this.targetPlayer = this.mg.owner(this.dst);
-    this.speed = this.mg.config().defaultNukeSpeed();
+
 
     // Record stats
     this.mg.stats().bombLaunch(this.player, this.targetPlayer, UnitType.MIRV);
@@ -75,6 +76,9 @@ export class MirvExecution implements Execution {
       const y = Math.max(0, this.mg.y(this.dst) - 500) + 50;
       this.separateDst = this.mg.ref(x, y);
       this.pathFinder.computeControlPoints(spawn, this.separateDst);
+      // Calculate speed for fixed travel time
+      const distance = this.mg.euclideanDist(spawn, this.separateDst);
+      this.speed = distance / this.MIRV_FIXED_TRAVEL_TIME;
 
       this.mg.displayIncomingUnit(
         this.nuke.id(),