feat(D-01/E): quickwins — debug toggle, HumanChairHelper move, collar equip

Q1: Remove F9 debug toggle from GltfAnimationApplier + delete dead
    GltfRenderLayer + remove keybind registration

Q2: Move HumanChairHelper from state/ to util/ — pure utility with
    no state dependency. 7 import updates.

Q3: Wire NECK collar equip flow in DataDrivenBondageItem:
    - Target must be tied up (V1 rule preserved)
    - Distance + line-of-sight validation
    - Owner added to NBT before equip via CollarHelper.addOwner()
    - V2EquipmentHelper handles conflict resolution
    - ModSounds.COLLAR_PUT played on success
    - OwnershipComponent.onEquipped registers in CollarRegistry

src/main/java/com/tiedup/remake/util/HumanChairHelper.java

@@ -0,0 +1,61 @@
+package com.tiedup.remake.util;
+
+import com.tiedup.remake.items.base.PoseType;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.item.ItemStack;
+
+/**
+ * Centralizes human chair NBT tag keys and resolution logic.
+ *
+ * <p>The human chair mode is stored as NBT tags on the dog bind item.
+ * This helper eliminates hardcoded string literals scattered across 7+ files.
+ */
+public final class HumanChairHelper {
+
+    /** NBT key indicating this bind is in human chair mode */
+    public static final String NBT_KEY = "humanChairMode";
+
+    /** NBT key for the locked facing direction (degrees) */
+    public static final String NBT_FACING_KEY = "humanChairFacing";
+
+    private HumanChairHelper() {}
+
+    /**
+     * Check if a bind item is in human chair mode.
+     *
+     * @param bind The bind ItemStack to check
+     * @return true if the bind has humanChairMode NBT set to true
+     */
+    public static boolean isActive(ItemStack bind) {
+        if (bind.isEmpty()) return false;
+        CompoundTag tag = bind.getTag();
+        return tag != null && tag.getBoolean(NBT_KEY);
+    }
+
+    /**
+     * Get the locked facing direction for human chair mode.
+     *
+     * @param bind The bind ItemStack
+     * @return The facing angle in degrees, or 0 if not set
+     */
+    public static float getFacing(ItemStack bind) {
+        if (bind.isEmpty()) return 0f;
+        CompoundTag tag = bind.getTag();
+        return tag != null ? tag.getFloat(NBT_FACING_KEY) : 0f;
+    }
+
+    /**
+     * Resolve the effective pose type, overriding DOG to HUMAN_CHAIR
+     * when the bind has humanChairMode enabled.
+     *
+     * @param base The base pose type from the bind item
+     * @param bind The bind ItemStack (checked for humanChairMode NBT)
+     * @return HUMAN_CHAIR if base is DOG and humanChairMode is active, otherwise base
+     */
+    public static PoseType resolveEffectivePose(PoseType base, ItemStack bind) {
+        if (base == PoseType.DOG && isActive(bind)) {
+            return PoseType.HUMAN_CHAIR;
+        }
+        return base;
+    }
+}