Refine terrain and pregeneration

- Add coherent river width variation and shape source and terminal pools.
- Preserve separated hydrology intervals when checking river connectivity.
- Reduce footprint sorting, engine context lookup, and terrain blending work.
- Reuse modded snapshot validation after content and registry checks.
- Explain production pack update staging and restart requirements.
- Retain pregeneration map updates before its desktop window opens.
- Improve pregeneration layout, coordinate hover, keyboard controls, and error details.
- Add the new desktop labels to every supported language catalog.
- Add the buildPsychoLT entry point for verified platform outputs.
- Cover terrain, validation, and desktop behavior with regression tests.

adapters/modded-common/src/main/java/art/arcane/iris/modded/ModdedGenerationHistoryStorage.java

@@ -6,10 +6,9 @@ import art.arcane.volmlib.nativelib.terrain.NativeWorld;
 import art.arcane.iris.pack.loading.IrisData;
 import art.arcane.iris.configuration.IrisSettings;
 import art.arcane.iris.pack.BrokenPackException;
-import art.arcane.iris.pack.PackValidationCache;
+import art.arcane.iris.pack.PackFingerprints;
 import art.arcane.iris.pack.PackValidationRegistry;
 import art.arcane.iris.pack.PackValidationResult;
-import art.arcane.iris.pack.PackValidator;
 import art.arcane.iris.world.history.GenerationEpoch;
 import art.arcane.iris.world.history.GenerationEpochContractFactory;
 import art.arcane.iris.world.history.GenerationHistory;
@@ -174,7 +173,7 @@ final class ModdedGenerationHistoryStorage {
     static ActivePack resolveActive(GenerationHistory history) throws IOException {
         GenerationEpoch epoch = history.activeEpoch();
         Path packRoot = normalize(history.activePackRoot());
-        validatePack(packRoot, epoch.packFingerprint());
+        validatePack(packRoot);
         validateDimension(packRoot, epoch);
         return new ActivePack(
                 packRoot,
@@ -184,13 +183,16 @@ final class ModdedGenerationHistoryStorage {
         );
     }
 
-    private static void validatePack(Path packRoot, String fingerprint) {
-        String contextFingerprint = PackValidationCache.contextFingerprint();
-        PackValidationResult validation = PackValidator.validate(packRoot.toFile());
-        PackValidationRegistry.publish(packRoot, validation, fingerprint, contextFingerprint);
+    static PackValidationResult validatePack(Path packRoot) {
+        PackValidationResult validation = PackValidationRegistry.getMatching(
+                packRoot, PackFingerprints.computePackTreeFingerprint(packRoot.toFile()));
+        if (validation == null) {
+            validation = ModdedStartup.validatePack(packRoot.toFile());
+        }
         if (!validation.isLoadable()) {
             throw new BrokenPackException(packRoot.toString(), validation.getBlockingErrors());
         }
+        return validation;
     }
 
     private static void validateDimension(

adapters/modded-common/src/main/java/art/arcane/iris/modded/service/ModdedPackUpdateService.java

@@ -119,7 +119,8 @@ public final class ModdedPackUpdateService implements ModdedTickableService {
                         + ", latest built-in release v" + update.version() + ".");
                 updates.add("Back up and review custom edits in " + new File(packsFolder, pack.name())
                         + "; close Studio, then update with /iris download pack=" + pack.name() + " overwrite=true.");
-                updates.add("Existing worlds retain their recorded production pack; this updates the authoring pack for new worlds.");
+                updates.add("Existing worlds retain their recorded production pack. Back up the complete world, then stage an update with /iris world update <dimension> "
+                        + pack.name() + " and restart the server to activate it.");
             }
         }
         notices = List.copyOf(updates);