Guardian boss bars; Phase 7 approved

Adrian, 2026-11-03: guardians get a boss health bar like the Wither's, which
also leads players to them. Every player within 128 blocks of a living
guardian sees a red bar of their own (GuardianBars): name, zone, how many
blocks away, and HP. The End boss keeps the dragon's bar.
guardian_appears_and_returns checks the bar appears and goes once beaten.
Self-tests and the island check pass.

Phase 7 approved ("Then begin with the next phase"); README status updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mod/src/main/kotlin/dev/cobblesurvival/CobbleSurvival.kt

@@ -21,6 +21,7 @@ import dev.cobblesurvival.selftest.SelfTest
 import dev.cobblesurvival.world.OnlyPokemon
 import dev.cobblesurvival.world.SharedLoot
 import dev.cobblesurvival.world.SpecialPokemon
+import dev.cobblesurvival.zone.GuardianBars
 import dev.cobblesurvival.zone.Guardians
 import dev.cobblesurvival.zone.InZoneCondition
 import dev.cobblesurvival.zone.LevelPressure
@@ -78,6 +79,7 @@ class CobbleSurvival {
         ZoneCondition.register()
         NeoForge.EVENT_BUS.addListener(Zones::onAddReloadListeners)
         Guardians.register()
+        GuardianBars.register()
         BossFights.register()
         BossToughness.register()
         EndBoss.register()

mod/src/main/kotlin/dev/cobblesurvival/selftest/GuardianTests.kt

@@ -4,6 +4,7 @@ import com.cobblemon.mod.common.battles.BattleBuilder
 import com.cobblemon.mod.common.battles.MoveActionResponse
 import com.cobblemon.mod.common.entity.pokemon.PokemonEntity
 import com.cobblemon.mod.common.util.isInBattle
+import dev.cobblesurvival.zone.GuardianBars
 import dev.cobblesurvival.zone.Guardians
 import dev.cobblesurvival.zone.Zones
 import net.minecraft.core.registries.BuiltInRegistries
@@ -49,6 +50,12 @@ object GuardianTests {
                 s.check(pokemon.isUncatchable()) { "the guardian can be caught" }
                 s.check(abs(pokemon.scaleModifier - definition.scale) < 0.01f) { "the guardian is size ${pokemon.scaleModifier}, not ${definition.scale}" }
                 s.check(expectedLevel == null || pokemon.level == expectedLevel) { "the guardian is level ${pokemon.level}, not $expectedLevel" }
+                // Adrian, 2026-11-03: a boss bar like the Wither's, with how far it is, leads the player to it.
+                GuardianBars.update(level)
+                val bar = GuardianBars.barFor(ZONE, player) ?: throw GameTestAssertException("no boss bar for the guardian 6 blocks away")
+                s.check(player in bar.players && bar.progress == 1f && bar.name.string.contains(pokemon.species.name)) {
+                    "the guardian's bar is wrong: '${bar.name.string}' at ${bar.progress}"
+                }
                 s.moveTo(player, guardian.x + 3, guardian.y, guardian.z)
             }
             .thenWaitUntil { s.check(guardian.pokemon.entity === guardian) { "the guardian has not ticked yet" } }
@@ -65,6 +72,7 @@ object GuardianTests {
             .thenIdle(100)
             .thenExecute {
                 s.check(Guardians.guardianOf(level, ZONE) == null) { "the guardian came back right away" }
+                s.check(GuardianBars.barFor(ZONE, player) == null) { "the beaten guardian's bar is still shown" }
                 Guardians.expireDefeatForTest(level, ZONE)
             }
             .thenWaitUntil {

mod/src/main/kotlin/dev/cobblesurvival/zone/GuardianBars.kt

@@ -0,0 +1,54 @@
+package dev.cobblesurvival.zone
+
+import net.minecraft.network.chat.Component
+import net.minecraft.server.level.ServerBossEvent
+import net.minecraft.server.level.ServerLevel
+import net.minecraft.server.level.ServerPlayer
+import net.minecraft.world.BossEvent
+import net.neoforged.neoforge.common.NeoForge
+import net.neoforged.neoforge.event.entity.player.PlayerEvent
+import net.neoforged.neoforge.event.tick.ServerTickEvent
+import java.util.UUID
+
+/**
+ * Every guardian shows a boss health bar, like the Wither's (Adrian, 2026-11-03), to each player within [RANGE]
+ * blocks: its name, its zone and how far away it is, so the bar leads players to it, and its HP, which falls in
+ * battle. Each player has a bar of their own, since the distance is theirs. The End boss has the dragon's bar
+ * ([dev.cobblesurvival.boss.EndBoss]).
+ */
+object GuardianBars {
+    const val RANGE = 128.0
+    private const val EVERY_TICKS = 10
+    private val bars = HashMap<Pair<String, UUID>, ServerBossEvent>()
+
+    fun register() {
+        NeoForge.EVENT_BUS.addListener<ServerTickEvent.Post> { if (it.server.tickCount % EVERY_TICKS == 0) update(it.server.overworld()) }
+        NeoForge.EVENT_BUS.addListener<PlayerEvent.PlayerLoggedOutEvent> { event ->
+            bars.keys.filter { it.second == event.entity.uuid }.forEach { bars.remove(it)?.removeAllPlayers() }
+        }
+    }
+
+    /** The bar [player] sees for the guardian of [zone], if any. */
+    fun barFor(zone: String, player: ServerPlayer): ServerBossEvent? = bars[zone to player.uuid]
+
+    fun update(level: ServerLevel) {
+        val seen = HashSet<Pair<String, UUID>>()
+        for (zone in Guardians.definitions.keys) {
+            val guardian = Guardians.guardianOf(level, zone) ?: continue
+            val pokemon = guardian.pokemon
+            for (player in level.players()) {
+                val distance = player.distanceTo(guardian)
+                if (distance > RANGE || player.isSpectator) continue
+                val key = zone to player.uuid
+                seen += key
+                val bar = bars.getOrPut(key) {
+                    ServerBossEvent(Component.empty(), BossEvent.BossBarColor.RED, BossEvent.BossBarOverlay.PROGRESS).also { it.addPlayer(player) }
+                }
+                bar.name = Component.translatableWithFallback("bossbar.cobblesurvival.guardian", "%s, guardian of %s (%s blocks away)",
+                    pokemon.getDisplayName(), Zones.byId[zone]?.name ?: zone, distance.toInt())
+                bar.progress = (pokemon.currentHealth.toFloat() / pokemon.maxHealth.coerceAtLeast(1)).coerceIn(0f, 1f)
+            }
+        }
+        bars.keys.filter { it !in seen }.forEach { bars.remove(it)?.removeAllPlayers() }
+    }
+}