Expose instability controls and diagnostics (#72)

docs/INSTABILITY_DIAGNOSTICS.md

@@ -0,0 +1,11 @@
+# Instability controls and diagnostics (Milestone 6, issue #72)
+
+The world-specific NeoForge server config (`serverconfig/rivencraft-server.toml`) is the global policy. `instability.enabled` stops all scheduled effects without changing a saved Age. `instability_providers.<id>` switches each Legacy card independently; these switches do not reroll frozen provider levels. The existing `instability_status_effects`, `instability_decay`, `instability_hazards`, `instability_meteor`, `instability_scorching`, and `instability_erosion` groups provide category policy and action limits. `instability.world_mutation`, hazard/meteor `block_damage`, `player_damage`, and `fire` settings control destructive behavior. `mobGriefing` and `doFireTick` still apply. Defaults retain the Legacy-active hazards; the scheduler, spawn protection, loaded-chunk checks, and per-effect caps remain Rivencraft safety adaptations. The dormant-in-Legacy erosion effect remains enabled for project testing but can be switched off.
+
+Configuration values are read during server operation, but editing the TOML on disk does not guarantee NeoForge will reload it. Restart the server or world after changing the file; `/reload` reloads data packs, not this server config. Per-Age commands below take effect on the next scheduler pass without a restart. A stopped provider does not refund or change the Age's score or saved plan. Existing owned status-effect leases are revoked on their next 20-tick check after global, category, provider, or Age disablement. In-flight meteors are cancelled when their Age or meteor provider is disabled. Existing block changes are not rolled back.
+
+Operators can inspect `/rivencraft age instability [dimension]`. The argument accepts an Age name (quote names containing spaces), a short path such as `fort`, or a full ID such as `rivencraft:age/fort`. Duplicate names require the full ID shown by `/rivencraft age list`. The command reports the frozen score and each saved contribution, the frozen provider IDs/levels and their *current* runtime eligibility, config limits, and whether this Age is enabled. "Eligible" does not promise an effect on the next tick: chance, cooldowns, loaded chunks, player presence, and protection still apply. An unavailable handler is reported as such instead of being mistaken for an active provider. Pre-scoring Ages remain neutral, and missing provider plans from older scored saves are migrated once as described in [runtime policy](INSTABILITY_RUNTIME.md). `/rivencraft age instability disable <dimension>` and `enable <dimension>` are operator-only and persist for that Age alone. Unknown dimensions are rejected. Neither command mutates a book, score, or provider plan.
+
+Newly bound Descriptive Books carry only a server-written numerical potential-instability summary for their tooltip and cover. The details and live enablement stay server-side in the operator command. Older written books receive the summary when opened through the server-approved book screen; until then, an absent tooltip score means "not yet synchronized," not zero. The score does not indicate whether effects are currently enabled.
+
+Manual check: create two scored Ages, disable one with the command, and inspect both. Only the selected Age should show "Age disabled"; its saved breakdown and plan should remain identical. Re-enable it, then switch an individual provider in the world config and restart. Its plan should remain identical while diagnostics show "provider config off." An old neutral Age should report score zero and no selected providers. A non-operator should be unable to invoke the mutation commands. Test tooltips both on a newly bound book and an older book after opening it once.

docs/INSTABILITY_RUNTIME.md

@@ -8,6 +8,8 @@ The server scheduler runs only for loaded `rivencraft:age/*` levels with a playe
 
 Issue #67 registers the non-world-mutating potion handlers; see [status-effect policy](INSTABILITY_STATUS_EFFECTS.md). Issue #68 adds configurable [colored decay](INSTABILITY_DECAY.md), enabled by default for newly generated configs. Issue #69 adds lightning and explosions; issue #70 adds [meteor, scorching, and erosion](INSTABILITY_ENVIRONMENTAL.md). The runtime rejects Overworld and preview dimension IDs; its player requirement excludes unattended snapshot chunk loaders. GameTests cover deterministic selection, save round-trips, score-only migration, unknown IDs, scope checks, fair admission, and action caps.
 
+Issue #72 adds [server config, per-Age controls, diagnostics, and book feedback](INSTABILITY_DIAGNOSTICS.md). Its operator controls never rewrite a frozen score or provider plan.
+
 # Lightning and explosions (#69)
 
 The `lightning` and `explosions` cards now run only in loaded Rivencraft Ages with players. Legacy rolled once per chunk per tick: explosions at 1/1000 and lightning at 1/5000 during thunder or 1/100000 otherwise. Each selected hazard card gets an independent roll every scheduler pass, rather than waiting for the rotating two-provider sample. The roll uses up to 81 already-loaded chunks near Age players and the exact probability of at least one Legacy opportunity over that many chunk-ticks. It permits at most one event per hazard type per pass. A per-Age saved sequence and last-event time prevent the same roll/event from replaying after a restart. Lightning also skips an existing bolt at the target.

gradle.properties

@@ -36,7 +36,7 @@ mod_name=Rivencraft
 # The license of the mod. Review your options at https://choosealicense.com/. All Rights Reserved is the default.
 mod_license=LGPL-3.0-or-later
 # The mod version. Rivencraft uses the x.y.z.b policy documented in README.md.
-mod_version=0.5.8.7
+mod_version=0.5.8.9
 immersive_portals_version=6.0.7
 terrablender_version=4.1.0.8
 serene_seasons_version_id=B6nTjh4b

src/main/java/net/dnorberg/rivencraft/book/AgeDecayProviders.java

@@ -51,6 +51,8 @@ public final class AgeDecayProviders {
         AgeDefinition age = AgeRegistrySavedData.get(level).findByDimension(level.dimension().location()).orElse(null);
         if (age == null) return -1;
         ResourceLocation id = id("decay" + color.getSerializedName());
+        if (!RivencraftConfig.instabilityEnabled() || !AgeInstabilityControls.get(level).enabled(age.id())
+                || !RivencraftConfig.instabilityProviderEnabled(id)) return -1;
         int changed = 0;
         for (int i = 0; i < Math.min(count, 32); i++) {
             AgeInstabilityRuntime.Budget budget = new AgeInstabilityRuntime.Budget(1);

src/main/java/net/dnorberg/rivencraft/book/AgeEnvironmentalProviders.java

@@ -60,6 +60,9 @@ public final class AgeEnvironmentalProviders {
         if (!AgeInstabilityRuntime.isAgeDimension(level.dimension().location())) return -1;
         AgeDefinition age = AgeRegistrySavedData.get(level).findByDimension(level.dimension().location()).orElse(null);
         if (age == null) return -1;
+        if (!RivencraftConfig.instabilityEnabled() || !AgeInstabilityControls.get(level).enabled(age.id())
+                || !RivencraftConfig.instabilityProviderEnabled(ResourceLocation.fromNamespaceAndPath(
+                        Rivencraft.MOD_ID, effect.equals("meteor") ? "meteors" : effect))) return 0;
         List<ChunkPos> chunks = AgeHazardProviders.loadedChunksNearPlayers(level, 16);
         if (chunks.isEmpty()) return 0;
         var context = new AgeInstabilityRuntime.Context(level, age, chunks,
@@ -165,7 +168,8 @@ public final class AgeEnvironmentalProviders {
             return;
         }
         AgeDefinition age = AgeRegistrySavedData.get(level).findByDimension(level.dimension().location()).orElse(null);
-        if (age == null) {
+        if (age == null || !AgeInstabilityControls.get(level).enabled(age.id())
+                || !RivencraftConfig.instabilityProviderEnabled(METEORS)) {
             ACTIVE.remove(level);
             return;
         }

src/main/java/net/dnorberg/rivencraft/book/AgeHazardProviders.java

@@ -96,6 +96,8 @@ public final class AgeHazardProviders {
                 || !AgeInstabilityRuntime.isAgeDimension(level.dimension().location())) return -1;
         AgeDefinition age = AgeRegistrySavedData.get(level).findByDimension(level.dimension().location()).orElse(null);
         if (age == null) return -1;
+        if (!RivencraftConfig.instabilityEnabled() || !AgeInstabilityControls.get(level).enabled(age.id())
+                || !RivencraftConfig.instabilityProviderEnabled(lightning ? LIGHTNING : EXPLOSIONS)) return -1;
         AgeHazardSavedData data = AgeHazardSavedData.get(level);
         if (!data.ready(lightning, level.getGameTime(), RivencraftConfig.hazardsMinInterval())) return 0;
         ChunkPos center = player.chunkPosition();

src/main/java/net/dnorberg/rivencraft/book/AgeInstabilityControls.java

@@ -0,0 +1,55 @@
+package net.dnorberg.rivencraft.book;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.util.datafix.DataFixTypes;
+import net.minecraft.world.level.saveddata.SavedData;
+
+/** Per-world operator overrides. Absence means enabled; scores and plans stay immutable. */
+public final class AgeInstabilityControls extends SavedData {
+    private static final String DATA_NAME = "rivencraft_instability_controls";
+    private static final Factory<AgeInstabilityControls> FACTORY = new Factory<>(
+            AgeInstabilityControls::new, AgeInstabilityControls::load, DataFixTypes.SAVED_DATA_MAP_DATA);
+    private final Set<UUID> disabled = new HashSet<>();
+
+    public static AgeInstabilityControls get(ServerLevel level) {
+        return level.getServer().overworld().getDataStorage().computeIfAbsent(FACTORY, DATA_NAME);
+    }
+
+    public boolean enabled(UUID ageId) {
+        return !disabled.contains(ageId);
+    }
+
+    public boolean setEnabled(UUID ageId, boolean enabled) {
+        boolean changed = enabled ? disabled.remove(ageId) : disabled.add(ageId);
+        if (changed) setDirty();
+        return changed;
+    }
+
+    static AgeInstabilityControls load(CompoundTag tag, HolderLookup.Provider registries) {
+        AgeInstabilityControls controls = new AgeInstabilityControls();
+        ListTag entries = tag.getList("DisabledAges", CompoundTag.TAG_COMPOUND);
+        for (int index = 0; index < entries.size(); index++) {
+            CompoundTag entry = entries.getCompound(index);
+            if (entry.hasUUID("Id")) controls.disabled.add(entry.getUUID("Id"));
+        }
+        return controls;
+    }
+
+    @Override
+    public CompoundTag save(CompoundTag tag, HolderLookup.Provider registries) {
+        ListTag entries = new ListTag();
+        disabled.stream().sorted().forEach(id -> {
+            CompoundTag entry = new CompoundTag();
+            entry.putUUID("Id", id);
+            entries.add(entry);
+        });
+        tag.put("DisabledAges", entries);
+        return tag;
+    }
+}

src/main/java/net/dnorberg/rivencraft/book/AgeInstabilityRuntime.java

@@ -52,7 +52,8 @@ public final class AgeInstabilityRuntime {
         if (!admitted(state.eligible, level.dimension().location(), tick / cooldown,
                 RivencraftConfig.instabilityMaxAges())) return;
         AgeDefinition age = AgeRegistrySavedData.get(level).findByDimension(level.dimension().location()).orElse(null);
-        if (age == null || age.instabilityPlan().providers().isEmpty()) return;
+        if (age == null || age.instabilityPlan().providers().isEmpty()
+                || !AgeInstabilityControls.get(level).enabled(age.id())) return;
         // Legacy's per-chunk hazards must not wait for the rotating two-provider sample.
         AgeHazardProviders.tickPlanned(level, age, tick);
         AgeEnvironmentalProviders.tickPlanned(level, age, tick);
@@ -74,6 +75,8 @@ public final class AgeInstabilityRuntime {
 
     /** Shared handler guard, including quarantine, for rotating and per-chunk provider lanes. */
     static boolean invoke(Context context, ResourceLocation id, int level) {
+        if (!RivencraftConfig.instabilityEnabled()
+                || !AgeInstabilityControls.get(context.level()).enabled(context.age().id())) return false;
         Handler handler = HANDLERS.get(id);
         if (handler == null) {
             if (!InstabilityProviderCatalog.contains(id) && UNKNOWN_LOGGED.add(id)) {
@@ -81,6 +84,7 @@ public final class AgeInstabilityRuntime {
             }
             return false;
         }
+        if (!RivencraftConfig.instabilityProviderEnabled(id)) return false;
         if (handler.worldMutating() && !RivencraftConfig.instabilityWorldMutation()) return false;
         long retryAfter = FAILURES.computeIfAbsent(context.level(), ignored -> new HashMap<>())
                 .getOrDefault(id, 0L);
@@ -107,6 +111,40 @@ public final class AgeInstabilityRuntime {
         return id.getNamespace().equals(Rivencraft.MOD_ID) && id.getPath().startsWith("age/");
     }
 
+    /** Current runtime state, distinct from the Age's immutable score and provider selection. */
+    public static String providerStatus(ServerLevel level, AgeDefinition age, ResourceLocation id) {
+        if (!RivencraftConfig.instabilityEnabled()) return "global config off";
+        if (!AgeInstabilityControls.get(level).enabled(age.id())) return "Age disabled";
+        Handler handler = HANDLERS.get(id);
+        if (handler == null) return "handler unavailable";
+        if (!RivencraftConfig.instabilityProviderEnabled(id)) return "provider config off";
+        if (handler.worldMutating() && !RivencraftConfig.instabilityWorldMutation()) return "world mutation off";
+        String path = id.getPath();
+        if (path.startsWith("decay") && !RivencraftConfig.decayEnabled()) return "decay config off";
+        if ((path.equals("lightning") || path.equals("explosions")) && !RivencraftConfig.hazardsEnabled())
+            return "hazards config off";
+        if (path.equals("meteors") && !RivencraftConfig.meteorEnabled()) return "meteor config off";
+        if (path.equals("burning") && !RivencraftConfig.scorchEnabled()) return "burning config off";
+        if (path.equals("erosion") && !RivencraftConfig.erosionEnabled()) return "erosion config off";
+        if (!path.startsWith("decay") && !path.equals("lightning") && !path.equals("explosions")
+                && !path.equals("meteors") && !path.equals("burning") && !path.equals("erosion")
+                && !path.equals("crumble") && !RivencraftConfig.statusEffectsEnabled())
+            return "status effects config off";
+        if (path.startsWith("enemy") && !RivencraftConfig.statusEffectsHostiles())
+            return "hostile status effects config off";
+        if (!path.startsWith("enemy") && !path.startsWith("decay") && !path.equals("lightning")
+                && !path.equals("explosions") && !path.equals("meteors") && !path.equals("burning")
+                && !path.equals("erosion") && !RivencraftConfig.statusEffectsPlayers()
+                && !RivencraftConfig.statusEffectsNonplayers())
+            return "status effect targets disabled";
+        ServerLevel ageLevel = level.getServer().getLevel(AgeDimensionService.dimensionKey(age));
+        if (ageLevel == null) return "Age unloaded";
+        if (ageLevel.players().isEmpty()) return "no players in Age";
+        long retryAfter = FAILURES.getOrDefault(ageLevel, Map.of()).getOrDefault(id, 0L);
+        if (ageLevel.getServer().getTickCount() < retryAfter) return "quarantined until tick " + retryAfter;
+        return "eligible; chance, cooldown, and protection still apply";
+    }
+
     static boolean admitted(List<ResourceLocation> eligible, ResourceLocation id, long run,
                             int maximum) {
         int index = eligible.indexOf(id);
@@ -122,6 +160,7 @@ public final class AgeInstabilityRuntime {
             ResourceLocation id = level.dimension().location();
             if (isAgeDimension(id) && !level.players().isEmpty()
                     && registry.findByDimension(id).filter(age -> !age.instabilityPlan().providers().isEmpty())
+                    .filter(age -> AgeInstabilityControls.get(level).enabled(age.id()))
                     .isPresent()) eligible.add(id);
         }
         eligible.sort(Comparator.comparing(ResourceLocation::toString));

src/main/java/net/dnorberg/rivencraft/book/AgeInstabilityRuntimeGameTests.java

@@ -59,6 +59,53 @@ public final class AgeInstabilityRuntimeGameTests {
         helper.succeed();
     }
 
+    @GameTest(template = "empty")
+    public static void perAgeControlsPersistWithoutChangingScoresOrOtherAges(GameTestHelper helper) {
+        UUID first = UUID.randomUUID();
+        UUID second = UUID.randomUUID();
+        AgeInstabilityControls controls = new AgeInstabilityControls();
+        helper.assertTrue(controls.enabled(first) && controls.enabled(second),
+                "Ages must be enabled by default");
+        helper.assertTrue(controls.setEnabled(first, false) && !controls.enabled(first)
+                        && controls.enabled(second), "Disabling one Age must not change another");
+        AgeInstabilityControls restored = AgeInstabilityControls.load(
+                controls.save(new CompoundTag(), helper.getLevel().registryAccess()),
+                helper.getLevel().registryAccess());
+        helper.assertTrue(!restored.enabled(first) && restored.enabled(second),
+                "The per-Age override must survive a save round trip");
+        helper.assertTrue(restored.setEnabled(first, true) && restored.enabled(first),
+                "Re-enabling must remove the override");
+
+        var oldAge = new AgeDefinition(first, "Old Age", 1L, AgeGenerationProfiles.STANDARD,
+                AgeDefinition.CURRENT_GENERATION_VERSION, 0L, AgeDefinition.dimensionId(first), null,
+                AgeTraits.LEGACY_DEFAULTS);
+        helper.assertValueEqual(oldAge.instability().score(), 0,
+                "A pre-scoring Age must remain neutral regardless of runtime controls");
+        helper.assertTrue(oldAge.instabilityPlan().providers().isEmpty(),
+                "Runtime controls must not generate providers for old Ages");
+        AgeInstabilityControls live = AgeInstabilityControls.get(helper.getLevel());
+        live.setEnabled(first, false);
+        helper.assertValueEqual(AgeInstabilityRuntime.providerStatus(helper.getLevel(), oldAge,
+                        ResourceLocation.parse("rivencraft:poison")), "Age disabled",
+                "Diagnostics must distinguish an Age override from the saved plan");
+        live.setEnabled(first, true);
+        helper.assertValueEqual(AgeInstabilityRuntime.providerStatus(helper.getLevel(), oldAge,
+                        ResourceLocation.parse("example:missing_handler")), "handler unavailable",
+                "Unknown saved providers must not be reported as active");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void instabilityControlCommandsRequireOperatorPermission(GameTestHelper helper) {
+        var server = helper.getLevel().getServer();
+        var command = server.getCommands().getDispatcher().getRoot().getChild("rivencraft");
+        helper.assertTrue(command != null, "Rivencraft commands must be registered on a dedicated server");
+        helper.assertTrue(!command.canUse(server.createCommandSourceStack().withPermission(0))
+                        && command.canUse(server.createCommandSourceStack().withPermission(2)),
+                "Non-operators cannot reach Age instability enable/disable commands");
+        helper.succeed();
+    }
+
     @GameTest(template = "empty")
     public static void ageScopeRotationAndActionBudgetAreBounded(GameTestHelper helper) {
         ResourceLocation first = ResourceLocation.parse("rivencraft:age/first");

src/main/java/net/dnorberg/rivencraft/book/AgeStatusEffectProviders.java

@@ -75,7 +75,7 @@ public final class AgeStatusEffectProviders {
         candidates.sort(Comparator.comparing(Entity::getUUID));
         LivingEntity target = candidates.get(random.nextInt(candidates.size()));
         if (!context.budget().claim() || !target.addEffect(instance)) return;
-        leases.add(new Lease(new WeakReference<>(target), instance,
+        leases.add(new Lease(id, new WeakReference<>(target), instance,
                 context.serverTick() + duration, spec.target()));
     }
 
@@ -100,7 +100,12 @@ public final class AgeStatusEffectProviders {
         if (event.getServer().getTickCount() % 20 != 0) return;
         boolean disabled = !RivencraftConfig.instabilityEnabled() || !RivencraftConfig.statusEffectsEnabled();
         long tick = event.getServer().getTickCount();
-        for (var entry : LEASES.entrySet()) prune(entry.getKey(), entry.getValue(), tick, disabled);
+        for (var entry : LEASES.entrySet()) {
+            AgeDefinition age = AgeRegistrySavedData.get(entry.getKey())
+                    .findByDimension(entry.getKey().dimension().location()).orElse(null);
+            prune(entry.getKey(), entry.getValue(), tick, disabled || age == null
+                    || !AgeInstabilityControls.get(entry.getKey()).enabled(age.id()));
+        }
         LEASES.values().removeIf(List::isEmpty);
     }
 
@@ -146,7 +151,8 @@ public final class AgeStatusEffectProviders {
                 iterator.remove();
                 continue;
             }
-            boolean revoke = removeAll || entity.level() != level
+            boolean revoke = removeAll || !RivencraftConfig.instabilityProviderEnabled(lease.provider())
+                    || entity.level() != level
                     || !allowedByPolicy(lease.target(), entity);
             if (revoke || tick >= lease.expiresAt()) {
                 removeOwnedEffect(entity, lease);
@@ -208,11 +214,11 @@ public final class AgeStatusEffectProviders {
 
     private enum Target { GENERAL, HOSTILE }
     private record Spec(Holder<MobEffect> effect, int legacyDuration, boolean global, Target target) {}
-    private record Lease(WeakReference<LivingEntity> entity, MobEffectInstance instance, long expiresAt,
+    private record Lease(ResourceLocation provider, WeakReference<LivingEntity> entity, MobEffectInstance instance, long expiresAt,
                          Target target, int amplifier, int originalDuration) {
-        private Lease(WeakReference<LivingEntity> entity, MobEffectInstance instance, long expiresAt,
+        private Lease(ResourceLocation provider, WeakReference<LivingEntity> entity, MobEffectInstance instance, long expiresAt,
                       Target target) {
-            this(entity, instance, expiresAt, target, instance.getAmplifier(), instance.getDuration());
+            this(provider, entity, instance, expiresAt, target, instance.getAmplifier(), instance.getDuration());
         }
     }
 }

src/main/java/net/dnorberg/rivencraft/client/ClientBookInteractionHandler.java

@@ -5,6 +5,7 @@ import net.dnorberg.rivencraft.client.screen.DescriptiveBookScreen;
 import net.dnorberg.rivencraft.block.entity.BookStandBlockEntity;
 import net.dnorberg.rivencraft.registry.ModBlocks;
 import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.minecraft.client.Minecraft;
 import net.minecraft.core.BlockPos;
 import net.minecraft.world.InteractionHand;
@@ -87,8 +88,12 @@ public final class ClientBookInteractionHandler {
                 currentBook = minecraft.player.getItemInHand(hand);
             }
             // Ignore delayed replies if the player has moved or replaced the book.
+            ItemStack currentWithoutSummary = currentBook.copy();
+            ItemStack replyWithoutSummary = payload.book().copy();
+            currentWithoutSummary.remove(ModDataComponents.AGE_INSTABILITY_SCORE.get());
+            replyWithoutSummary.remove(ModDataComponents.AGE_INSTABILITY_SCORE.get());
             if (!currentBook.is(ModItems.DESCRIPTIVE_BOOK.get())
-                    || !ItemStack.isSameItemSameComponents(currentBook, payload.book())) {
+                    || !ItemStack.isSameItemSameComponents(currentWithoutSummary, replyWithoutSummary)) {
                 return;
             }
             minecraft.setScreen(payload.fromStand()

src/main/java/net/dnorberg/rivencraft/client/screen/DescriptiveBookScreen.java

@@ -54,6 +54,7 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo
     private final List<SymbolDisplayMetadata> writingSymbols;
     private final boolean pageFree;
     private final String author;
+    private final Integer instabilityScore;
     private final InteractionHand hand;
     private final BlockPos bookStandPos;
     private DestinationPreviewRenderer preview;
@@ -74,6 +75,7 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo
         this.writingSymbols = List.copyOf(writingSymbols);
         pageFree = writing.entries().stream().noneMatch(entry -> entry.kind() == WritingEntry.Kind.SYMBOL);
         author = book.get(ModDataComponents.BOOK_AUTHOR.get());
+        instabilityScore = book.get(ModDataComponents.AGE_INSTABILITY_SCORE.get());
         this.hand = hand;
         bookStandPos = null;
     }
@@ -88,6 +90,7 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo
         this.writingSymbols = List.copyOf(writingSymbols);
         pageFree = writing.entries().stream().noneMatch(entry -> entry.kind() == WritingEntry.Kind.SYMBOL);
         author = book.get(ModDataComponents.BOOK_AUTHOR.get());
+        instabilityScore = book.get(ModDataComponents.AGE_INSTABILITY_SCORE.get());
         hand = InteractionHand.MAIN_HAND;
         this.bookStandPos = bookStandPos.immutable();
     }
@@ -250,7 +253,12 @@ public final class DescriptiveBookScreen extends Screen implements ExplorableBoo
         int detailsY = drawWrappedWithoutShadow(graphics,
                 author == null || author.isBlank()
                         ? Component.translatable("screen.rivencraft.age.unknown_author")
-                        : Component.literal(author), x + 10, nameEnd + 2, 100) + 10;
+                        : Component.literal(author), x + 10, nameEnd + 2, 100) + 4;
+        if (instabilityScore != null) {
+            detailsY = drawWrappedWithoutShadow(graphics,
+                    Component.translatable("item.rivencraft.descriptive_book.instability", instabilityScore),
+                    x, detailsY, 110, instabilityScore > 0 ? UNRESOLVED_TEXT_COLOR : BOOK_TEXT_COLOR) + 6;
+        }
         if (!pageFree) return;
         if (generationProfile != null) {
             Component profileName = generationProfile.getNamespace().equals("rivencraft")

src/main/java/net/dnorberg/rivencraft/command/RivencraftCommands.java

@@ -9,12 +9,17 @@ import net.dnorberg.rivencraft.book.AgeHazardProviders;
 import net.dnorberg.rivencraft.book.AgeEnvironmentalProviders;
 import net.dnorberg.rivencraft.book.AgeDimensionService;
 import net.dnorberg.rivencraft.book.AgeRegistrySavedData;
+import net.dnorberg.rivencraft.book.AgeInstabilityControls;
+import net.dnorberg.rivencraft.book.AgeInstabilityRuntime;
+import net.dnorberg.rivencraft.config.RivencraftConfig;
 import net.minecraft.commands.Commands;
 import net.minecraft.commands.CommandSourceStack;
 import com.mojang.brigadier.builder.LiteralArgumentBuilder;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.neoforged.neoforge.event.RegisterCommandsEvent;
+import java.util.List;
+import java.util.Locale;
 
 /** Administrative commands for inspecting and safely unloading persistent Ages. */
 public final class RivencraftCommands {
@@ -30,21 +35,23 @@ public final class RivencraftCommands {
                         .then(Commands.literal("instability")
                                 .executes(context -> inspectInstability(context.getSource(),
                                         context.getSource().getLevel().dimension().location().toString()))
+                                .then(Commands.literal("enable")
+                                        .then(Commands.argument("dimension", StringArgumentType.string())
+                                                .suggests((context, builder) -> suggestAges(context.getSource(), builder))
+                                                .executes(context -> setInstability(context.getSource(),
+                                                        StringArgumentType.getString(context, "dimension"), true))))
+                                .then(Commands.literal("disable")
+                                        .then(Commands.argument("dimension", StringArgumentType.string())
+                                                .suggests((context, builder) -> suggestAges(context.getSource(), builder))
+                                                .executes(context -> setInstability(context.getSource(),
+                                                        StringArgumentType.getString(context, "dimension"), false))))
                                 .then(Commands.argument("dimension", StringArgumentType.string())
-                                        .suggests((context, builder) -> {
-                                            AgeRegistrySavedData.get(context.getSource().getLevel()).definitions()
-                                                    .forEach(age -> builder.suggest(age.dimensionId().toString()));
-                                            return builder.buildFuture();
-                                        })
+                                        .suggests((context, builder) -> suggestAges(context.getSource(), builder))
                                         .executes(context -> inspectInstability(context.getSource(),
                                                 StringArgumentType.getString(context, "dimension")))))
                         .then(Commands.literal("unload")
                                 .then(Commands.argument("dimension", StringArgumentType.string())
-                                        .suggests((context, builder) -> {
-                                            AgeRegistrySavedData.get(context.getSource().getLevel()).definitions()
-                                                    .forEach(age -> builder.suggest(age.dimensionId().toString()));
-                                            return builder.buildFuture();
-                                        })
+                                        .suggests((context, builder) -> suggestAges(context.getSource(), builder))
                                         .executes(context -> unloadAge(
                                                 context.getSource(),
                                                 StringArgumentType.getString(context, "dimension")
@@ -100,16 +107,8 @@ public final class RivencraftCommands {
     }
 
     private static int unloadAge(net.minecraft.commands.CommandSourceStack source, String requestedDimension) {
-        ResourceLocation dimension = ResourceLocation.tryParse(requestedDimension);
-        if (dimension == null) {
-            source.sendFailure(Component.literal("Invalid dimension id: " + requestedDimension));
-            return 0;
-        }
-        AgeDefinition age = AgeRegistrySavedData.get(source.getLevel()).findByDimension(dimension).orElse(null);
-        if (age == null) {
-            source.sendFailure(Component.literal("Unknown Rivencraft Age: " + dimension));
-            return 0;
-        }
+        AgeDefinition age = resolveAge(source, requestedDimension);
+        if (age == null) return 0;
 
         AgeDimensionService.UnloadResult result = AgeDimensionService.unload(source.getServer(), age);
         return switch (result) {
@@ -131,27 +130,96 @@ public final class RivencraftCommands {
     }
 
     private static int inspectInstability(CommandSourceStack source, String requestedDimension) {
-        ResourceLocation dimension = ResourceLocation.tryParse(requestedDimension);
-        if (dimension == null) {
-            source.sendFailure(Component.literal("Invalid dimension id: " + requestedDimension));
-            return 0;
-        }
-        AgeDefinition age = AgeRegistrySavedData.get(source.getLevel()).findByDimension(dimension).orElse(null);
-        if (age == null) {
-            source.sendFailure(Component.literal("Unknown Rivencraft Age: " + dimension));
-            return 0;
-        }
+        AgeDefinition age = resolveAge(source, requestedDimension);
+        if (age == null) return 0;
         var totals = age.instability().totals();
         source.sendSuccess(() -> Component.literal(age.name() + " — " + age.dimensionId()), false);
         source.sendSuccess(() -> Component.literal("Instability: base " + totals.baseScore()
                 + ", stability bonus " + totals.stabilityBonus()
                 + ", penalty " + totals.instabilityPenalty()
                 + ", effective " + totals.effectiveScore()), false);
+        boolean enabled = AgeInstabilityControls.get(source.getLevel()).enabled(age.id());
+        source.sendSuccess(() -> Component.literal("Runtime: " + (enabled ? "Age enabled" : "Age disabled")
+                + ", global " + (RivencraftConfig.instabilityEnabled() ? "enabled" : "disabled")
+                + "; saved score and plan are unchanged by controls"), false);
+        source.sendSuccess(() -> Component.literal("Score breakdown (saved schema v"
+                + age.instability().version() + "):"), false);
+        age.instability().breakdown().forEach(part -> source.sendSuccess(() -> Component.literal(
+                "  " + (part.pageIndex() < 0 ? "Age" : "page " + (part.pageIndex() + 1))
+                        + " +" + part.points() + " " + part.reason() + ": " + part.detail()), false));
+        source.sendSuccess(() -> Component.literal("Selected providers (saved plan v"
+                + age.instabilityPlan().version() + "): " + age.instabilityPlan().providers().size()), false);
+        age.instabilityPlan().providers().forEach(provider -> source.sendSuccess(() -> Component.literal(
+                "  " + provider.id() + " level " + provider.level() + " — "
+                        + AgeInstabilityRuntime.providerStatus(source.getLevel(), age, provider.id())), false));
+        if (age.instabilityPlan().providers().isEmpty()) source.sendSuccess(() -> Component.literal(
+                "  No providers selected; an old neutral Age stays neutral."), false);
+        source.sendSuccess(() -> Component.literal("Limits: cooldown " + RivencraftConfig.instabilityCooldown()
+                + " ticks, " + RivencraftConfig.instabilityMaxAges() + " Ages/tick, "
+                + RivencraftConfig.instabilityMaxProviders() + " providers/Age, "
+                + RivencraftConfig.instabilityMaxActions() + " actions/Age, level cap "
+                + RivencraftConfig.instabilityMaxLevel()), false);
         source.sendSuccess(() -> Component.literal("Mutable player bonuses: disabled (no active Legacy registration)"),
                 false);
         return totals.effectiveScore();
     }
 
+    private static java.util.concurrent.CompletableFuture<com.mojang.brigadier.suggestion.Suggestions> suggestAges(
+            CommandSourceStack source, com.mojang.brigadier.suggestion.SuggestionsBuilder builder) {
+        AgeRegistrySavedData.get(source.getLevel()).definitions()
+                .forEach(age -> {
+                    builder.suggest(age.dimensionId().toString());
+                    if (!age.name().contains(" ")) builder.suggest(age.name());
+                });
+        return builder.buildFuture();
+    }
+
+    /** Bare input is an Age name or short path, never a minecraft-namespace resource ID. */
+    static List<AgeDefinition> matchingAges(List<AgeDefinition> ages, String requested) {
+        String input = requested.strip();
+        if (input.isEmpty()) return List.of();
+        if (input.contains(":")) {
+            ResourceLocation id = ResourceLocation.tryParse(input);
+            return id == null ? List.of() : ages.stream()
+                    .filter(age -> age.dimensionId().equals(id)).toList();
+        }
+        List<AgeDefinition> names = ages.stream()
+                .filter(age -> age.name().equalsIgnoreCase(input)).toList();
+        if (!names.isEmpty()) return names;
+        String path = input.toLowerCase(Locale.ROOT);
+        if (!path.startsWith("age/")) path = "age/" + path;
+        String expectedPath = path;
+        return ages.stream().filter(age -> age.dimensionId().getPath().equals(expectedPath)).toList();
+    }
+
+    private static AgeDefinition resolveAge(CommandSourceStack source, String requested) {
+        List<AgeDefinition> matches = matchingAges(
+                AgeRegistrySavedData.get(source.getLevel()).definitions(), requested);
+        if (matches.size() == 1) return matches.getFirst();
+        if (matches.size() > 1) {
+            source.sendFailure(Component.literal("Ambiguous Age name '" + requested
+                    + "'. Use its full dimension ID from /rivencraft age list."));
+        } else {
+            source.sendFailure(Component.literal("Unknown Rivencraft Age '" + requested
+                    + "'. Use its name or dimension ID from /rivencraft age list."));
+        }
+        return null;
+    }
+
+    private static int setInstability(CommandSourceStack source, String requestedDimension, boolean enabled) {
+        if (!source.hasPermission(2)) {
+            source.sendFailure(Component.literal("Operator permission is required to change Age instability."));
+            return 0;
+        }
+        AgeDefinition age = resolveAge(source, requestedDimension);
+        if (age == null) return 0;
+        boolean changed = AgeInstabilityControls.get(source.getLevel()).setEnabled(age.id(), enabled);
+        source.sendSuccess(() -> Component.literal(age.name() + " instability "
+                + (enabled ? "enabled" : "disabled") + (changed ? "" : " (already set)")
+                + ". The saved score and provider plan are unchanged."), true);
+        return 1;
+    }
+
     private static int pulseDecay(net.minecraft.commands.CommandSourceStack source, String colorName, int attempts) {
         DecayBlock.Color color;
         try {

src/main/java/net/dnorberg/rivencraft/command/RivencraftCommandsGameTests.java

@@ -0,0 +1,53 @@
+package net.dnorberg.rivencraft.command;
+
+import java.util.List;
+import java.util.UUID;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.book.AgeDefinition;
+import net.dnorberg.rivencraft.book.AgeGenerationProfiles;
+import net.dnorberg.rivencraft.book.AgeTraits;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.neoforged.neoforge.gametest.GameTestHolder;
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;
+
+/** Command-facing Age lookup regression checks. */
+@GameTestHolder(Rivencraft.MOD_ID)
+@PrefixGameTestTemplate(false)
+public final class RivencraftCommandsGameTests {
+    private RivencraftCommandsGameTests() {}
+
+    @GameTest(template = "empty")
+    public static void bareAgeNameDoesNotBecomeMinecraftResourceId(GameTestHelper helper) {
+        AgeDefinition fort = age("Fort", "fort");
+        AgeDefinition tower = age("Tower", "tower");
+        List<AgeDefinition> ages = List.of(fort, tower);
+        for (String query : List.of("fort", "Fort", "age/fort", "rivencraft:age/fort")) {
+            helper.assertValueEqual(RivencraftCommands.matchingAges(ages, query), List.of(fort),
+                    "Age lookup must accept its name, short path, and full dimension ID");
+        }
+        helper.assertTrue(RivencraftCommands.matchingAges(ages, "minecraft:fort").isEmpty(),
+                "An explicit wrong namespace must not resolve to a Rivencraft Age");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void duplicateNamesRequireFullDimensionId(GameTestHelper helper) {
+        AgeDefinition first = age("Fort", "fort");
+        AgeDefinition second = age("Fort", "fort_2");
+        List<AgeDefinition> ages = List.of(first, second);
+        helper.assertValueEqual(RivencraftCommands.matchingAges(ages, "fort").size(), 2,
+                "Duplicate display names must remain ambiguous, not silently pick an Age");
+        helper.assertValueEqual(RivencraftCommands.matchingAges(ages, "rivencraft:age/fort_2"),
+                List.of(second), "A full dimension ID must select the intended duplicate");
+        helper.succeed();
+    }
+
+    private static AgeDefinition age(String name, String path) {
+        UUID id = UUID.randomUUID();
+        return new AgeDefinition(id, name, 1L, AgeGenerationProfiles.STANDARD,
+                AgeDefinition.CURRENT_GENERATION_VERSION, 0L,
+                net.minecraft.resources.ResourceLocation.parse("rivencraft:age/" + path), null,
+                AgeTraits.LEGACY_DEFAULTS);
+    }
+}

src/main/java/net/dnorberg/rivencraft/config/RivencraftConfig.java

@@ -1,5 +1,8 @@
 package net.dnorberg.rivencraft.config;
 
+import java.util.HashMap;
+import java.util.Map;
+import net.minecraft.resources.ResourceLocation;
 import net.neoforged.neoforge.common.ModConfigSpec;
 
 /** Server-configurable gameplay policies. */
@@ -56,6 +59,7 @@ public final class RivencraftConfig {
     private static final ModConfigSpec.BooleanValue SCORCH_PLAYERS;
     private static final ModConfigSpec.IntValue SCORCH_MAX_TARGETS;
     private static final ModConfigSpec.BooleanValue EROSION_ENABLED;
+    private static final Map<String, ModConfigSpec.BooleanValue> INSTABILITY_PROVIDERS = new HashMap<>();
 
     static {
         ModConfigSpec.Builder builder = new ModConfigSpec.Builder();
@@ -170,6 +174,19 @@ public final class RivencraftConfig {
                         "Ages with a destructive instability score may spread adjacent fluid into one safe block per pass.")
                 .define("enabled", true);
         builder.pop();
+        builder.push("instability_providers");
+        for (String provider : new String[] {
+                "blindness", "blindness_global", "enemyregen_global", "enemyresist_global",
+                "fatigue", "fatigue_global", "hunger", "hunger_global", "nausea", "nausea_global",
+                "poison", "poison_global", "slow", "slow_global", "weakness", "weakness_global",
+                "wither", "wither_global", "burning", "crumble", "decayblue", "decaypurple",
+                "decayred", "decaywhite", "explosions", "lightning", "meteors", "erosion"
+        }) {
+            INSTABILITY_PROVIDERS.put(provider, builder.comment(
+                    "Allow this saved provider to run. Disabling it does not change an Age's frozen plan.")
+                    .define(provider, true));
+        }
+        builder.pop();
         SPEC = builder.build();
     }
 
@@ -193,6 +210,11 @@ public final class RivencraftConfig {
     }
 
     public static boolean instabilityEnabled() { return INSTABILITY_ENABLED.get(); }
+    public static boolean instabilityProviderEnabled(ResourceLocation id) {
+        ModConfigSpec.BooleanValue value = id.getNamespace().equals("rivencraft")
+                ? INSTABILITY_PROVIDERS.get(id.getPath()) : null;
+        return value != null && value.get();
+    }
     public static boolean instabilityWorldMutation() { return INSTABILITY_WORLD_MUTATION.get(); }
     public static int instabilityCooldown() { return INSTABILITY_COOLDOWN.get(); }
     public static int instabilityMaxAges() { return INSTABILITY_MAX_AGES.get(); }

src/main/java/net/dnorberg/rivencraft/item/DescriptiveBookItem.java

@@ -112,6 +112,11 @@ public final class DescriptiveBookItem extends Item {
                 ? Component.translatable("item.rivencraft.descriptive_book.unwritten")
                 : Component.translatable("item.rivencraft.descriptive_book.age", age.name());
         tooltipComponents.add(status.withStyle(ChatFormatting.GRAY));
+        Integer instability = stack.get(ModDataComponents.AGE_INSTABILITY_SCORE.get());
+        if (age != null && instability != null) {
+            tooltipComponents.add(Component.translatable("item.rivencraft.descriptive_book.instability", instability)
+                    .withStyle(instability > 0 ? ChatFormatting.DARK_RED : ChatFormatting.DARK_GREEN));
+        }
         stack.getOrDefault(ModDataComponents.LINK_PROPERTIES.get(), LinkProperties.NONE)
                 .forDescriptiveBook().appendTooltip(tooltipComponents);
     }

src/main/java/net/dnorberg/rivencraft/network/ModNetworking.java

@@ -111,6 +111,11 @@ public final class ModNetworking {
                 access.stack().set(ModDataComponents.AGE_GENERATION_PROFILE.get(), definition.generationProfile());
                 access.sync().run();
         }
+        if (definition != null && !java.util.Objects.equals(
+                access.stack().get(ModDataComponents.AGE_INSTABILITY_SCORE.get()), definition.instability().score())) {
+            access.stack().set(ModDataComponents.AGE_INSTABILITY_SCORE.get(), definition.instability().score());
+            access.sync().run();
+        }
         // Requests run on the same server thread as Age creation. A request queued
         // during generation can only open the finished book, never a stale client copy.
         player.inventoryMenu.broadcastChanges();
@@ -170,8 +175,10 @@ public final class ModNetworking {
 
             access.stack().set(ModDataComponents.AGE_REFERENCE.get(), reference);
             access.stack().set(ModDataComponents.BOOK_AUTHOR.get(), player.getGameProfile().getName());
-            AgeRegistrySavedData.get(player.serverLevel()).find(reference.id()).ifPresent(definition ->
-                    access.stack().set(ModDataComponents.AGE_GENERATION_PROFILE.get(), definition.generationProfile()));
+            AgeRegistrySavedData.get(player.serverLevel()).find(reference.id()).ifPresent(definition -> {
+                access.stack().set(ModDataComponents.AGE_GENERATION_PROFILE.get(), definition.generationProfile());
+                access.stack().set(ModDataComponents.AGE_INSTABILITY_SCORE.get(), definition.instability().score());
+            });
             access.stack().set(DataComponents.CUSTOM_NAME, Component.literal(title));
             access.sync().run();
             player.level().playSound(null, player.blockPosition(), SoundEvents.BOOK_PAGE_TURN, SoundSource.PLAYERS, 1.0F, 1.0F);

src/main/java/net/dnorberg/rivencraft/registry/ModDataComponents.java

@@ -81,6 +81,13 @@ public final class ModDataComponents {
                     .networkSynchronized(ByteBufCodecs.STRING_UTF8)
                     .cacheEncoding()
                     .build());
+    /** Server-written display summary only; detailed scoring and provider plans remain server-owned. */
+    public static final DeferredHolder<DataComponentType<?>, DataComponentType<Integer>> AGE_INSTABILITY_SCORE =
+            DATA_COMPONENTS.register("age_instability_score", () -> DataComponentType.<Integer>builder()
+                    .persistent(Codec.intRange(0, Integer.MAX_VALUE))
+                    .networkSynchronized(ByteBufCodecs.VAR_INT)
+                    .cacheEncoding()
+                    .build());
     public static final DeferredHolder<DataComponentType<?>, DataComponentType<Integer>> INK_REMAINING =
             DATA_COMPONENTS.register("ink_remaining", () -> DataComponentType.<Integer>builder()
                     .persistent(Codec.intRange(0, 16))

src/main/resources/assets/rivencraft/lang/en_us.json

@@ -2,6 +2,7 @@
   "item.rivencraft.descriptive_book": "Descriptive Book",
   "item.rivencraft.descriptive_book.unwritten": "Unwritten",
   "item.rivencraft.descriptive_book.age": "%s",
+  "item.rivencraft.descriptive_book.instability": "Instability: %s (potential)",
   "item.rivencraft.linking_book": "Linking Book",
   "item.rivencraft.linking_book.unbound": "Unbound — sneak-use to bind",
   "item.rivencraft.linking_book.destination": "%s (%s, %s, %s)",