Phase 7: practice-boss and guardian-reset commands; steadier spawn survey

Adrian (2026-11-02): a way to force-spawn the bosses.

- /cobblesurvival boss <zone|end>: a practice copy next to you (same
  species, level, size, attacks; no drops, not the guardian's defeat).
- /cobblesurvival guardians reset <zone>: despawns the zone's guardian
  and clears its defeat, so it appears again when someone comes near
  (Guardians.reset, formerly resetForTest).
- Self-test practice_bosses_spawn.
- spawn_survey stands on the ground below trees: on a mangrove's roots
  it found no natural ground and nothing could spawn at the Mire sample.

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

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

@@ -32,8 +32,21 @@ object BossTests {
         SelfTestCase("boss_attacks_land_and_stop_with_the_battle", 400, ::landAndStop),
         SelfTestCase("boss_arena_leaving_loses", 400, ::arena),
         SelfTestCase("end_boss_replaces_the_dragon", 200, ::endBoss),
+        SelfTestCase("practice_bosses_spawn", 20, ::practice),
     )
 
+    /** `/cobblesurvival boss <zone|end>`: a copy that fights like the real boss, for every guardian and the End. */
+    private fun practice(s: Scenario) {
+        for (which in Guardians.definitions.keys + "end") {
+            val entity = dev.cobblesurvival.boss.BossCommands.spawnPractice(s.level, s.at(7.5, 1.0, 7.5), which)
+                ?: throw GameTestAssertException("no practice boss for $which")
+            s.check(BossFights.defOf(entity) != null && entity.pokemon.isUncatchable()) { "the practice $which is no uncatchable boss" }
+            s.check(entity.pokemon.persistentData.getString(Guardians.TAG).isEmpty()) { "the practice $which counts as the real guardian" }
+            entity.discard()
+        }
+        s.helper.succeed()
+    }
+
     private fun implemented(species: String) = PokemonSpecies.getByName(species)?.implemented == true
 
     private fun coverage(s: Scenario) {

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

@@ -26,8 +26,8 @@ object GuardianTests {
         val definition = Guardians.definitions[ZONE] ?: throw GameTestAssertException("no guardian defined for $ZONE")
         val sample = Zones.samples[ZONE] ?: throw GameTestAssertException("no sample point for $ZONE")
         val level = s.level
-        Guardians.resetForTest(level, ZONE)
-        s.afterTest { Guardians.resetForTest(level, ZONE) }
+        Guardians.reset(level, ZONE)
+        s.afterTest { Guardians.reset(level, ZONE) }
 
         val player = s.player()
         s.give(player, s.pokemon("mewtwo", 100, "earthquake"))  // a spread move needs no target

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

@@ -108,13 +108,29 @@ object ZoneTests {
         }.thenSucceed()
     }
 
+    /**
+     * The ground at [x] [z], below any tree: standing on a mangrove's roots or logs, the survey once found no natural
+     * ground around it, so nothing could spawn (2026-11-02).
+     */
+    private fun ground(level: net.minecraft.server.level.ServerLevel, x: Int, z: Int): BlockPos {
+        var y = level.getHeight(Heightmap.Types.MOTION_BLOCKING_NO_LEAVES, x, z)
+        while (y > level.minBuildHeight) {
+            val below = level.getBlockState(BlockPos(x, y - 1, z))
+            val tree = below.`is`(net.minecraft.tags.BlockTags.LOGS) || below.`is`(net.minecraft.tags.BlockTags.LEAVES) ||
+                below.`is`(net.minecraft.world.level.block.Blocks.MANGROVE_ROOTS)
+            if (below.blocksMotion() && !tree) break
+            y--
+        }
+        return BlockPos(x, y, z)
+    }
+
     /** What can spawn around the sample right now, and how many spawnable positions Cobblemon found there. */
     private fun survey(s: Scenario, player: ServerPlayer, zoneId: String, sample: ZoneSample): Pair<Set<SpawnDetail>, Int> {
         val level = s.level
         // Generate the chunks around the sample, then find where to stand.
         for (dx in -2..2) for (dz in -2..2) level.getChunk((sample.x shr 4) + dx, (sample.z shr 4) + dz)
         val stand = if (sample.y == null) {
-            BlockPos(sample.x, level.getHeight(Heightmap.Types.MOTION_BLOCKING_NO_LEAVES, sample.x, sample.z), sample.z)
+            ground(level, sample.x, sample.z)
         } else {
             caveFloor(s, zoneId, sample, sample.y)
                 ?: throw GameTestAssertException("no open $zoneId cave near ${sample.x} ${sample.y} ${sample.z}")