Add forced simulation command

src/main/java/com/livingworld/commands/LivingWorldCommandRoot.java

@@ -55,9 +55,14 @@ public final class LivingWorldCommandRoot {
                                 .executes(context -> listModules(
                                         context.getSource(), moduleRegistry))))
                 .then(Commands.literal("simulate")
-                        .then(Commands.argument("ticks", IntegerArgumentType.integer(1, 1000))
-                                .executes(context -> placeholder(
-                                        context.getSource(), "Forced simulation is not connected yet.")))));
+                        .then(Commands.argument(
+                                        "ticks",
+                                        IntegerArgumentType.integer(
+                                                1, SimulationManager.MAX_FORCED_SIMULATION_TICKS))
+                                .executes(context -> SimulateCommand.execute(
+                                        context.getSource(),
+                                        simulationManager,
+                                        IntegerArgumentType.getInteger(context, "ticks"))))));
     }
 
     private static int showStatus(

src/main/java/com/livingworld/commands/SimulateCommand.java

@@ -0,0 +1,47 @@
+package com.livingworld.commands;
+
+import net.minecraft.commands.CommandSourceStack;
+import net.minecraft.network.chat.Component;
+
+import com.livingworld.core.simulation.SimulationManager;
+
+/**
+ * Runs a bounded number of forced Living World simulation cycles.
+ */
+public final class SimulateCommand {
+
+    private SimulateCommand() {
+    }
+
+    public static int execute(
+            CommandSourceStack source,
+            SimulationManager simulationManager,
+            int ticks) {
+        if (source == null) {
+            throw new IllegalArgumentException("source must not be null");
+        }
+        if (simulationManager == null) {
+            throw new IllegalArgumentException("simulationManager must not be null");
+        }
+
+        if (ticks <= 0 || ticks > SimulationManager.MAX_FORCED_SIMULATION_TICKS) {
+            source.sendFailure(Component.literal(
+                    "Ticks must be between 1 and "
+                            + SimulationManager.MAX_FORCED_SIMULATION_TICKS + "."));
+            return 0;
+        }
+
+        try {
+            simulationManager.runForcedSimulationTicks(ticks);
+            source.sendSuccess(
+                    () -> Component.literal(
+                            "Ran " + ticks + " Living World simulation ticks."),
+                    true);
+            return ticks;
+        } catch (RuntimeException exception) {
+            source.sendFailure(Component.literal(
+                    "Simulation failed: " + exception.getMessage()));
+            return 0;
+        }
+    }
+}

src/main/java/com/livingworld/core/simulation/SimulationManager.java

@@ -23,6 +23,8 @@ import com.livingworld.regions.Region;
  */
 public final class SimulationManager {
 
+    public static final int MAX_FORCED_SIMULATION_TICKS = 1000;
+
     private final SimulationScheduler scheduler;
     private final RegionManager regionManager;
     private final ModuleRegistry moduleRegistry;
@@ -152,9 +154,12 @@ public final class SimulationManager {
      * Runs forced simulation ticks for debugging or testing.
      */
     public void runForcedSimulationTicks(int ticks) {
-        if (ticks <= 0 || ticks > 100) {
+        if (ticks <= 0 || ticks > MAX_FORCED_SIMULATION_TICKS) {
             throw new IllegalArgumentException(
-                String.format("forced ticks must be in range [1, 100], got: %d", ticks));
+                String.format(
+                        "forced ticks must be in range [1, %d], got: %d",
+                        MAX_FORCED_SIMULATION_TICKS,
+                        ticks));
         }
 
         for (int i = 0; i < ticks; i++) {

src/test/java/com/livingworld/core/simulation/SimulationManagerTest.java

@@ -3,6 +3,8 @@ package com.livingworld.core.simulation;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -86,6 +88,22 @@ class SimulationManagerTest {
         assertEquals(0, fixture.scheduler.getMinecraftTickCounter());
     }
 
+    @Test
+    void forcedTicksAcceptSafeMaximumAndRejectValuesOutsideRange() {
+        Fixture fixture = new Fixture(25);
+
+        assertDoesNotThrow(() -> fixture.manager.runForcedSimulationTicks(
+                SimulationManager.MAX_FORCED_SIMULATION_TICKS));
+        assertEquals(
+                SimulationManager.MAX_FORCED_SIMULATION_TICKS,
+                fixture.timeService.getSimulationTick());
+        assertThrows(IllegalArgumentException.class,
+                () -> fixture.manager.runForcedSimulationTicks(0));
+        assertThrows(IllegalArgumentException.class,
+                () -> fixture.manager.runForcedSimulationTicks(
+                        SimulationManager.MAX_FORCED_SIMULATION_TICKS + 1));
+    }
+
     @Test
     void timeBudgetRequeuesJobsNotYetProcessed() {
         Fixture fixture = new Fixture(1);