refactor: organise assets, tidy player.gd, unbreak fresh import

Assets grouped by role, within the constraint that FBX materials resolve
their textures by path relative to the FBX itself (verified by forcing a
reimport and reading back the albedo paths):

  assets/level/   scene.fbx + Level1_v1.fbx + the platform maps they look
                  up as siblings
  assets/logos/   the three attribution logos
  assets/         chara_red.fbx, background.fbx — these reach up into
                  ../sourceimages and so cannot move
  sourcefiles/    scene.blend, behind a .gdignore

The .blend move is a bug fix, not tidying. Godot hands every importable
.blend to a headless Blender, and that call never returns on this project
— a fresh clone stalls on first import, and the machine still had orphaned
Blender processes from an earlier attempt. Nothing loads the .blend: the
level geometry is baked into level_1.tscn.

player.gd: spell out ct/bt/d/ix/a, type the physics step, group the
members, and point the blue skin at sourceimages/low_blue_mat_* — the same
files assets/Chara_blue/ was a byte-identical copy of.

Co-Authored-By: Claude Opus 5 <[email protected]>

sourcefiles/scene.blend.import

@@ -0,0 +1,63 @@
+[remap]
+
+importer="scene"
+importer_version=1
+type="PackedScene"
+uid="uid://valx6a5gep7b"
+path="res://.godot/imported/scene.blend-b11bd894821666c7e7b8236eab67765e.scn"
+
+[deps]
+
+source_file="res://assets/level/scene.blend"
+dest_files=["res://.godot/imported/scene.blend-b11bd894821666c7e7b8236eab67765e.scn"]
+
+[params]
+
+nodes/root_type=""
+nodes/root_name=""
+nodes/root_script=null
+mesh_library/use_node_names_as_mesh_names=false
+array_mesh/deduplicate_surfaces=true
+nodes/apply_root_scale=true
+nodes/root_scale=1.0
+nodes/import_as_skeleton_bones=false
+nodes/use_name_suffixes=true
+nodes/use_node_type_suffixes=true
+meshes/ensure_tangents=true
+meshes/generate_lods=true
+meshes/create_shadow_meshes=true
+meshes/light_baking=1
+meshes/lightmap_texel_size=0.2
+meshes/force_disable_compression=false
+skins/use_named_skins=true
+animation/import=true
+animation/fps=30
+animation/trimming=false
+animation/remove_immutable_tracks=true
+animation/import_rest_as_RESET=false
+import_script/path=""
+materials/extract=0
+materials/extract_format=0
+materials/extract_path=""
+_subresources={}
+blender/nodes/visible=0
+blender/nodes/active_collection_only=false
+blender/nodes/punctual_lights=true
+blender/nodes/cameras=true
+blender/nodes/custom_properties=true
+blender/nodes/modifiers=1
+blender/meshes/vertex_colors=1
+blender/meshes/uvs=true
+blender/meshes/normals=true
+blender/meshes/export_geometry_nodes_instances=false
+blender/meshes/gpu_instances=false
+blender/meshes/tangents=true
+blender/meshes/skins=2
+blender/meshes/export_bones_deforming_mesh_only=false
+blender/materials/unpack_enabled=true
+blender/materials/export_materials=1
+blender/animation/limit_playback=true
+blender/animation/always_sample=true
+blender/animation/group_tracks=true
+gltf/naming_version=2
+gltf/texture_map_mode=1