Scene-based assets

Character and background entries now reference PackedScene resources. A scene may contain textures, video, Spine, Live2D, shaders, or custom nodes.

Character scenes should inherit KonadoCharacterSceneBase and override _apply_status(resolved_status_name, original_status_name); scenes that can validate state names should also override _has_status. _has_status must be side-effect-free and idempotent because a delayed transition may query it when accepting the request and again at final commit. Scenes that safely expose pure textures may implement both _get_current_status_transition_frame and _get_status_transition_frame for a true premultiplied-alpha blend. Live2D, Spine, video, and custom scenes that cannot provide side-effect-free frames automatically use the safe fade-out/apply/fade-in path. Neither path duplicates the character scene. See Change Actor State for configuration. Optional stage motion belongs in a KonadoActorMotionLayer scene whose AnimationPlayer animation names match KS motion names. A stage motion with no explicit duration plays at the animation's authored length, a duration of 0 disables it, and a positive duration rescales it.

Each transition-frame call must return a newly created, independent frame; do not reuse and mutate the same frame for both endpoints.

Background scenes should inherit KonadoBackgroundSceneBase. Assign the scene to background_scene; add uniquely named KonadoCameraMarker nodes when camera commands are needed. These nodes only store target positions and zoom values; the dialogue template's camera renders the scene. Do not replace a custom rendering camera with KonadoCameraMarker. Built-in transitions are handled by KonadoBackgroundTransitionLayer. Transitions capture the complete scene through SubViewport by default. Select DIRECT_TEXTURE only when the rendered background is exactly equivalent to one unmodified source texture; backgrounds with layout, transforms, cameras, animation, materials, tinting, or multiple drawables must keep VIEWPORT_CAPTURE.

Configure the corresponding character_scene or background_scene in the resource list. Keep node paths stable and make scene roots fill their parent when they are UI-based.