Docs: gap-list pass bookend — underwater clips/bubbles/ambience/camera-drag session log, Blender 5.1 zero-takes export gotcha (cookbook + CLAUDE.md)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.claude/skills/art-dev/references/blender-cookbook.md

@@ -222,7 +222,7 @@ bpy.ops.wm.save_as_mainfile(filepath=SRC + r"\<Type>_<Name>.blend")
 bpy.ops.export_scene.gltf(filepath=SRC + r"\SM_<Name>.glb", export_format='GLB',
                           use_selection=True, export_apply=True, export_yup=True)
 ```
-Skinned/animation export → the per-action FBX recipe in [[blender-mcp-and-unity-mcp-v10]] (`bake_anim_use_all_bones`, `bake_anim_force_startend_keying`, `apply_scale_options='FBX_SCALE_UNITS'`, `add_leaf_bones=False`; Unity import `CreateFromThisModel`). **Never export into `Assets/` while a Unity session may be live** — write to `ArtSource/`, bake in later.
+Skinned/animation export → the per-action FBX recipe in [[blender-mcp-and-unity-mcp-v10]] (`bake_anim_use_all_bones`, `bake_anim_force_startend_keying`, `apply_scale_options='FBX_SCALE_UNITS'`, `add_leaf_bones=False`; Unity import `CreateFromThisModel`). **★ Blender 5.1: ALSO pass `bake_anim_use_nla_strips=False`** — slotted actions break the `use_all_actions=False` active-action path and the FBX exports with ZERO takes (silent, ~50KB vs ~270KB); with NLA strips off the exporter samples the evaluated scene over the frame range (set the scene range + `action_slot` per action first). Unity side: `ModelImporter.defaultClipAnimations` only enumerates takes AFTER a rig-typed `SaveAndReimport` (two-pass; see `PlayerRigTools.ImportUnderwaterClips`). **Never export into `Assets/` while a Unity session may be live** — write to `ArtSource/`, bake in later.
 
 ## 11. In-engine verification (Unity URP render harness) — the REAL A0 check