Added Studio hotload command

- /iris studio hotload and its refresh alias reload the open Studio pack on Bukkit
- Bukkit hotload refuses while Studio entry, pause or close is pending
- Modded servers register the same hotload and refresh commands
- Modded hotload reports busy while that Studio is already hotloading
- Hotload messages and help entries are localized in every language file
- Bukkit artifact verification reads the jar task output
- Multiplexor takes the Bukkit artifact from the packedJar task
- BukkitTestServer shares one-time registry setup across tests
- Tests and a gameplay scenario cover both hotload commands

adapters/bukkit/plugin/src/main/java/art/arcane/iris/command/CommandStudio.java

@@ -104,6 +104,7 @@ import java.util.function.Consumer;
 import art.arcane.iris.localization.IrisLanguage;
 import art.arcane.iris.localization.BukkitCommandMessages;
 import art.arcane.volmlib.util.localization.MessageArgument;
+import art.arcane.volmlib.util.localization.LanguageAudience;
 import art.arcane.iris.localization.BukkitCommandMessagesExtended;
 @Director(name = "studio", aliases = {"std", "s"}, description = "Studio Commands", descriptionKey = "iris.director.commandstudio.director.studio_commands")
 public class CommandStudio implements DirectorExecutor {
@@ -203,6 +204,22 @@ public class CommandStudio implements DirectorExecutor {
         }));
     }
 
+    @Director(description = "Hotload the active Studio pack", descriptionKey = "iris.director.commandstudio.director.hotload_active_studio_pack", aliases = {"refresh"}, origin = DirectorOrigin.BOTH)
+    public void hotload() {
+        VolmitSender commandSender = sender();
+        IrisProject project = Iris.service(StudioSVC.class).getActiveProject();
+        PlatformChunkGenerator generator = project == null ? null : project.getActiveProvider();
+        if (generator == null) {
+            commandSender.sendMessage(IrisLanguage.text(BukkitCommandMessages.COMMAND_STUDIO_NO_OPEN_STUDIO_PROJECTS));
+            return;
+        }
+
+        UUID audience = LanguageAudience.current();
+        commandSender.sendMessage(IrisLanguage.text(BukkitCommandMessages.COMMAND_STUDIO_HOTLOADING));
+        generator.hotloadAsync().whenComplete((ignored, failure) ->
+                LanguageAudience.run(audience, () -> sendHotloadResult(commandSender, failure)));
+    }
+
     @Director(description = "Toggle your Studio debug scoreboard", descriptionKey = "iris.director.commandstudio.director.toggle_your_studio_debug_scoreboard", aliases = {"board", "sidebar", "sb"}, origin = DirectorOrigin.PLAYER)
     public void scoreboard() {
         Player target = player();
@@ -642,6 +659,16 @@ public class CommandStudio implements DirectorExecutor {
         sender().sendMessage(IrisLanguage.text(BukkitCommandMessagesExtended.COMMAND_STUDIO_DONE, MessageArgument.untrusted("value", report.getPath())));
     }
 
+    private void sendHotloadResult(VolmitSender commandSender, Throwable failure) {
+        if (failure != null) {
+            Iris.reportError(failure);
+            commandSender.sendMessage(IrisLanguage.text(BukkitCommandMessages.COMMAND_STUDIO_HOTLOAD_FAILED,
+                    MessageArgument.untrusted("value", String.valueOf(failure.getMessage()))));
+            return;
+        }
+        commandSender.sendMessage(IrisLanguage.text(BukkitCommandMessages.COMMAND_STUDIO_HOTLOADED));
+    }
+
     private PlatformChunkGenerator resolveProfileGenerator(IrisDimension dimension) {
         StudioSVC studioService = Iris.service(StudioSVC.class);
         if (studioService != null && studioService.isProjectOpen()) {

adapters/bukkit/plugin/src/test/gameplay/studio-manual-hotload.mjs

@@ -0,0 +1,72 @@
+import { readFile, writeFile } from 'node:fs/promises'
+import path from 'node:path'
+import { setup, openStudio, closeStudio, sampleTerrain, readJson, writeJson,
+  logPosition, logSince } from './studio-support.mjs'
+
+async function hotload(context, fixture, active, command) {
+  const before = await readJson(fixture.manifestPath(active.key))
+  const response = await context.command(command, /^Studio hotloaded\.$|^Studio hotload failed:/, 90000)
+  context.expect(response === 'Studio hotloaded.', 'The manual Studio command did not complete successfully', { command, response })
+  const after = await readJson(fixture.manifestPath(active.key))
+  context.expect(after.pendingActivationId === null, 'The manual hotload completed with a pending activation')
+  context.report.iris.manualHotloads.push({ command, response,
+    before: before.activeActivationId, after: after.activeActivationId })
+  return after
+}
+
+export default {
+  name: 'iris-studio-manual-hotload',
+  description: 'Refresh an open Studio through hotload and its refresh alias, verify terrain, and reject commands without a Studio.',
+  async run(context) {
+    const fixture = await setup(context)
+    const biomeFile = path.join(fixture.pack, 'biomes', 'flat.json')
+    const original = await readFile(biomeFile, 'utf8')
+    const logOffset = await logPosition(fixture)
+    const processId = (await context.observe()).processId
+    context.report.iris.manualHotloads = []
+    let active
+    try {
+      await context.step('Reject hotload without an open Studio', async () => {
+        await context.command('/iris studio hotload', /^No open studio projects\.$/, 10000)
+      })
+      await context.step('Open Studio and hotload an unchanged pack', async () => {
+        active = await openStudio(context, fixture)
+        await sampleTerrain(context, fixture, 0, fixture.state.material)
+        await hotload(context, fixture, active, '/iris studio hotload')
+        await sampleTerrain(context, fixture, 4096, fixture.state.material)
+      })
+      await context.step('Refresh an edited pack and inspect newly generated terrain', async () => {
+        const before = await readJson(fixture.manifestPath(active.key))
+        const biome = await readJson(biomeFile)
+        biome.name = 'Manual hotload terrain'
+        biome.layers[0].palette[0].block = 'minecraft:gold_block'
+        await writeJson(biomeFile, biome)
+        await hotload(context, fixture, active, '/iris studio refresh')
+        const after = await fixture.wait(async () => {
+          const manifest = await readJson(fixture.manifestPath(active.key))
+          return manifest.activeActivationId !== before.activeActivationId && manifest.pendingActivationId === null ? manifest : false
+        }, 'The edited Studio pack did not become active', 90000)
+        context.report.iris.activations.push({ before: before.activeActivationId,
+          after: after.activeActivationId, material: 'gold_block' })
+        await sampleTerrain(context, fixture, 16384, 'gold_block')
+        await sampleTerrain(context, fixture, 0, fixture.state.material)
+      })
+      await context.step('Close Studio and reject another refresh', async () => {
+        await closeStudio(context, fixture, active)
+        active = undefined
+        await context.command('/iris studio refresh', /^No open studio projects\.$/, 10000)
+        await context.command('/minecraft:seed', /Seed:/i, 10000)
+      })
+      context.expect((await context.observe()).processId === processId, 'The server restarted during manual Studio hotload')
+      const log = await logSince(fixture, logOffset)
+      context.expect(!/Studio generation update failed|Studio hotload failed|Unable to (capture terrain|save the terrain boundary)|ClosedChannelException|Chunk system error|server has stopped responding|could not acquire its engine runtime|Failed to list files/i.test(log),
+        'Manual Studio hotload emitted a generation, snapshot, storage, or watchdog failure')
+    } finally {
+      try {
+        if (active) await closeStudio(context, fixture, active)
+      } finally {
+        await writeFile(biomeFile, original)
+      }
+    }
+  }
+}

adapters/bukkit/plugin/src/test/java/art/arcane/iris/command/CommandStudioHotloadTest.java

@@ -0,0 +1,112 @@
+package art.arcane.iris.command;
+
+import art.arcane.iris.Iris;
+import art.arcane.iris.platform.bukkit.plugin.VolmitSender;
+import art.arcane.iris.platform.generation.PlatformChunkGenerator;
+import art.arcane.iris.studio.StudioSVC;
+import art.arcane.iris.studio.workspace.IrisProject;
+import art.arcane.volmlib.util.director.annotations.Director;
+import art.arcane.volmlib.util.localization.LanguageAudience;
+import org.junit.Test;
+import org.mockito.MockedStatic;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.lang.reflect.Method;
+import java.io.File;
+import java.util.concurrent.CompletableFuture;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+public class CommandStudioHotloadTest {
+    @Test
+    public void hotloadAndRefreshReportWhenNoStudioIsOpen() throws Exception {
+        RecordingSender sender = new RecordingSender();
+        StudioSVC studio = mock(StudioSVC.class);
+        Method hotload = CommandStudio.class.getDeclaredMethod("hotload");
+        assertTrue(List.of(hotload.getAnnotation(Director.class).aliases()).contains("refresh"));
+
+        try (MockedStatic<Iris> iris = mockStatic(Iris.class)) {
+            iris.when(() -> Iris.service(StudioSVC.class)).thenReturn(studio);
+            hotload.invoke(new TestCommand(sender));
+            assertTrue(sender.messages.getLast(), sender.messages.getLast().contains("No open studio"));
+        }
+    }
+
+    @Test
+    public void completionFeedbackWaitsForTheHotload() {
+        assertCompletionFeedback(null, "Studio hotloaded.");
+    }
+
+    @Test
+    public void failedHotloadReportsFailureAndLogsTheCause() {
+        assertCompletionFeedback(new IllegalStateException("Invalid pack"), "Studio hotload failed: Invalid pack");
+    }
+
+    private void assertCompletionFeedback(Throwable failure, String expected) {
+        RecordingSender sender = new RecordingSender();
+        StudioSVC studio = mock(StudioSVC.class);
+        PlatformChunkGenerator generator = mock(PlatformChunkGenerator.class);
+        IrisProject project = new IrisProject(new File("tutorial"));
+        project.setActiveProvider(generator);
+        CompletableFuture<Void> pending = new CompletableFuture<>();
+        UUID audience = UUID.randomUUID();
+        when(studio.getActiveProject()).thenReturn(project);
+        when(generator.hotloadAsync()).thenReturn(pending);
+
+        try (MockedStatic<Iris> iris = mockStatic(Iris.class)) {
+            iris.when(() -> Iris.service(StudioSVC.class)).thenReturn(studio);
+            LanguageAudience.run(audience, () -> new TestCommand(sender).hotload());
+            assertNull(LanguageAudience.current());
+
+            verify(generator).hotloadAsync();
+            assertEquals(1, sender.messages.size());
+            assertTrue(sender.messages.getFirst().contains("Hotloading Studio"));
+            if (failure == null) {
+                pending.complete(null);
+            } else {
+                pending.completeExceptionally(failure);
+                iris.verify(() -> Iris.reportError(failure));
+            }
+            assertEquals(2, sender.messages.size());
+            assertTrue(sender.messages.getLast(), sender.messages.getLast().contains(expected));
+            assertEquals(List.of(audience, audience), sender.audiences);
+            assertNull(LanguageAudience.current());
+        }
+    }
+
+    private static final class TestCommand extends CommandStudio {
+        private final VolmitSender sender;
+
+        private TestCommand(VolmitSender sender) {
+            this.sender = sender;
+        }
+
+        @Override
+        public VolmitSender sender() {
+            return sender;
+        }
+    }
+
+    private static final class RecordingSender extends VolmitSender {
+        private final List<String> messages = new ArrayList<>();
+        private final List<UUID> audiences = new ArrayList<>();
+
+        private RecordingSender() {
+            super(null);
+        }
+
+        @Override
+        public void sendMessage(String message) {
+            messages.add(message);
+            audiences.add(LanguageAudience.current());
+        }
+    }
+}