修复了一些bug

internal/blockentity/blockentity.go

@@ -45,7 +45,12 @@ const CookTime = 200
 
 // FuelTicks 燃料燃烧时长表（tick，物品与背包.md §6）。
 var FuelTicks = map[string]int{
-	"coal": 1600,
+	"coal":           1600,
+	"oak_planks":     300,
+	"oak_log":        300,
+	"stick":          100,
+	"crafting_table": 300,
+	"chest":          300,
 }
 
 // New 创建方块实体（按类型分配槽位）。
@@ -118,7 +123,7 @@ func (e *Entity) CanInsert(slot int, s item.Stack, reg *item.Registry) bool {
 		case SlotInput:
 			return e.Slots[slot].Empty() || e.Slots[slot].Name == s.Name
 		case SlotOutput:
-			return e.Slots[slot].Empty() || e.Slots[slot].Name == s.Name
+			return false
 		}
 	}
 	return inventory.CanMerge(e.Slots[slot], s) || e.Slots[slot].Empty()
@@ -159,6 +164,47 @@ func (e *Entity) Remove(slot, count int) item.Stack {
 	return out
 }
 
+// Snapshot 存档快照（存档格式.md §2 block_entities）。
+type Snapshot struct {
+	X, Y, Z      int32        `json:"x"`
+	Kind         string       `json:"kind"`
+	Slots        []item.Stack `json:"slots,omitempty"`
+	BurnTicks    int          `json:"burn_ticks,omitempty"`
+	BurnMaxTicks int          `json:"burn_max,omitempty"`
+	CookTicks    int          `json:"cook_ticks,omitempty"`
+}
+
+// Serialize 导出快照。
+func (e *Entity) Serialize() Snapshot {
+	if e == nil {
+		return Snapshot{}
+	}
+	kind := "chest"
+	if e.Kind == KindFurnace {
+		kind = "furnace"
+	}
+	slots := make([]item.Stack, len(e.Slots))
+	copy(slots, e.Slots)
+	return Snapshot{
+		X: e.X, Y: e.Y, Z: e.Z, Kind: kind, Slots: slots,
+		BurnTicks: e.BurnTicks, BurnMaxTicks: e.BurnMaxTicks, CookTicks: e.CookTicks,
+	}
+}
+
+// Deserialize 从快照重建。
+func Deserialize(s Snapshot) *Entity {
+	kind := KindChest
+	if s.Kind == "furnace" {
+		kind = KindFurnace
+	}
+	e := New(kind, s.X, s.Y, s.Z)
+	for i := 0; i < len(s.Slots) && i < len(e.Slots); i++ {
+		e.Slots[i] = s.Slots[i]
+	}
+	e.BurnTicks, e.BurnMaxTicks, e.CookTicks = s.BurnTicks, s.BurnMaxTicks, s.CookTicks
+	return e
+}
+
 // String 描述（调试）。
 func (e *Entity) String() string {
 	return fmt.Sprintf("blockentity(%d @%d,%d,%d)", e.Kind, e.X, e.Y, e.Z)

internal/blockentity/blockentity_test.go

@@ -90,4 +90,19 @@ func TestFurnaceSlotRules(t *testing.T) {
 	if !f.CanInsert(SlotFuel, item.Stack{Name: "coal", Count: 1}, reg) {
 		t.Fatal("燃料槽应接受煤炭")
 	}
+	if !f.CanInsert(SlotFuel, item.Stack{Name: "oak_planks", Count: 1}, reg) {
+		t.Fatal("燃料槽应接受木板")
+	}
+	if f.CanInsert(SlotOutput, item.Stack{Name: "iron_ingot", Count: 1}, reg) {
+		t.Fatal("输出格不应放入")
+	}
+}
+
+func TestSerializeRoundtrip(t *testing.T) {
+	e := NewChest(1, 2, 3)
+	e.Slots[0] = item.Stack{Name: "stick", Count: 7}
+	got := Deserialize(e.Serialize())
+	if got.Kind != KindChest || got.Slots[0].Count != 7 {
+		t.Fatalf("箱子快照往返失败: %+v", got)
+	}
 }