feat(hemp): wild patches in plains/forest + chest seed injection

Two new ways to find hemp seeds without already having any:

1. Worldgen: minecraft:scatter_feature spawns 1-3 mature
   silverlabs:hemp_crop blocks on grass/dirt in plains/forest/birch/
   flower_forest biomes (~14% scatter chance per chunk surface pass).
2. Chest injection: 8% chance per chest first-open to plant 1-3 seeds
   in a random empty slot. Tracked per-chest via world dynamic property
   (rolling cap of 500 entries) so each chest only contributes once.

Bedrock has no loot-table merge mechanism so we can't add seeds to
vanilla village chests without losing their vanilla loot — script
injection sidesteps that and stays version-independent.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hemp-addon/hemp_BP/feature_rules/hemp_patch_rule.json

@@ -0,0 +1,35 @@
+{
+  "format_version": "1.21.0",
+  "minecraft:feature_rules": {
+    "description": {
+      "identifier": "silverlabs:hemp_patch_rule",
+      "places_feature": "silverlabs:hemp_patch_feature"
+    },
+    "conditions": {
+      "placement_pass": "surface_pass",
+      "minecraft:biome_filter": [
+        {
+          "any_of": [
+            { "test": "has_biome_tag", "value": "plains" },
+            { "test": "has_biome_tag", "value": "forest" },
+            { "test": "has_biome_tag", "value": "birch" },
+            { "test": "has_biome_tag", "value": "flower_forest" }
+          ]
+        },
+        { "test": "has_biome_tag", "operator": "!=", "value": "monster" }
+      ]
+    },
+    "distribution": {
+      "iterations": 1,
+      "scatter_chance": 14,
+      "x": { "distribution": "uniform", "extent": [0, 16] },
+      "y": {
+        "distribution": "fixed_grid",
+        "extent": [0, 64],
+        "grid_offset": 0,
+        "step_size": 1
+      },
+      "z": { "distribution": "uniform", "extent": [0, 16] }
+    }
+  }
+}

hemp-addon/hemp_BP/features/hemp_patch_feature.json

@@ -0,0 +1,12 @@
+{
+  "format_version": "1.21.0",
+  "minecraft:scatter_feature": {
+    "description": { "identifier": "silverlabs:hemp_patch_feature" },
+    "iterations": 3,
+    "scatter_chance": 65,
+    "x": { "distribution": "uniform", "extent": [-3, 4] },
+    "y": 0,
+    "z": { "distribution": "uniform", "extent": [-3, 4] },
+    "places_feature": "silverlabs:hemp_single_feature"
+  }
+}

hemp-addon/hemp_BP/features/hemp_single_feature.json

@@ -0,0 +1,27 @@
+{
+  "format_version": "1.21.0",
+  "minecraft:single_block_feature": {
+    "description": { "identifier": "silverlabs:hemp_single_feature" },
+    "places_block": {
+      "name": "silverlabs:hemp_crop",
+      "states": {
+        "silverlabs:hemp_age": 4,
+        "silverlabs:hemp_top": false
+      }
+    },
+    "enforce_survivability_rules": true,
+    "enforce_placement_rules": true,
+    "may_attach_to": {
+      "min_sides_must_attach": 1,
+      "top": [
+        "minecraft:grass_block",
+        "minecraft:dirt",
+        "minecraft:podzol",
+        "minecraft:coarse_dirt"
+      ]
+    },
+    "may_replace": [
+      "minecraft:air"
+    ]
+  }
+}

hemp-addon/hemp_BP/scripts/main.js

@@ -681,6 +681,62 @@ world.afterEvents.itemCompleteUse.subscribe((event) => {
   }
 });
 
+// --- Chest loot injection: first-time-open chests sometimes contain seeds ---
+//     Bedrock has no merge-loot-table mechanism, so we hook chest opens and
+//     deposit hemp_seeds with low probability into a random empty slot.
+//     Tracking is per-chest via a world dynamic property holding a JSON list
+//     of "dim:x:y:z" keys; pruned to a rolling cap to bound storage.
+const CHEST_TYPES = new Set(["minecraft:chest", "minecraft:trapped_chest"]);
+const CHEST_SEED_CHANCE = 0.08;
+const SEEDED_PROP = "hemp_seeded_chests_v1";
+const SEEDED_CAP = 500;
+
+function chestKey(block) {
+  const l = block.location;
+  return `${block.dimension.id}:${l.x}:${l.y}:${l.z}`;
+}
+function loadSeededChests() {
+  try {
+    const raw = world.getDynamicProperty(SEEDED_PROP);
+    return new Set(raw ? JSON.parse(raw) : []);
+  } catch (_) { return new Set(); }
+}
+function saveSeededChests(set) {
+  // Prune oldest if over cap (Set preserves insertion order in JS)
+  if (set.size > SEEDED_CAP) {
+    const arr = Array.from(set).slice(set.size - SEEDED_CAP);
+    set = new Set(arr);
+  }
+  try {
+    world.setDynamicProperty(SEEDED_PROP, JSON.stringify(Array.from(set)));
+  } catch (_) {}
+}
+
+world.afterEvents.playerInteractWithBlock.subscribe((event) => {
+  const block = event.block;
+  if (!block || !CHEST_TYPES.has(block.typeId)) return;
+  // Only on the open hand (not while holding an item, to avoid placing-into events firing twice)
+  const stack = event.itemStack;
+  if (stack) return;
+  const key = chestKey(block);
+  const seeded = loadSeededChests();
+  if (seeded.has(key)) return;
+  seeded.add(key);
+  saveSeededChests(seeded);
+  if (!chance(CHEST_SEED_CHANCE)) return;
+  // Try to insert into a random empty slot
+  let inv;
+  try { inv = block.getComponent("minecraft:inventory")?.container; } catch (_) { return; }
+  if (!inv) return;
+  const empties = [];
+  for (let i = 0; i < inv.size; i++) if (!inv.getItem(i)) empties.push(i);
+  if (empties.length === 0) return;
+  const slot = empties[rand(empties.length)];
+  const count = 1 + rand(3); // 1-3 seeds
+  try { inv.setItem(slot, new ItemStack(SEEDS, count)); } catch (_) {}
+  // No chat ping — let the player discover the seeds organically.
+});
+
 system.run(() => {
   world.sendMessage("§a[Hemp] §7Hemp pack loaded.");
 });