Add new test file for phase 19 scenery with unique identifier

docs/ideas/feature_backlog.md

@@ -36,6 +36,10 @@ Priorities are recommendations for discussion, not a committed release schedule.
 
 9. **Group props into set pieces** — **Status:** Parked · **Suggested priority:** Low. **Intent:** Let children group objects for organization and moving together within one scene. **Rationale:** Deferred until later at the user's direction. Scene-only groups make arranging furnished sets faster. In PLAY, each item keeps its own physics and interaction; picking up one prop does not move the rest, and stopping PLAY returns the grouped items to their authored arrangement. Reusable set-piece assets are deferred. This is **Phase 17d** in the [Phase 17 — Props for Storytelling plan](../plans/phase_17_props_for_storytelling.md). **Connections:** `scripts/stage/stage_selection.gd`, `scripts/editors/stage/sandbox_stage.gd`, `scripts/stage/stage_scene_io.gd`.
 
+10. **Stage-relative prop and scenery scale** — **Status:** Planned — Phase 19 addition; UI approved · **Suggested priority:** Medium. **Intent:** Establish one recognizable Stage scale based on the standard stickman, then author each asset at the size its role calls for so ordinary placements start correctly without routine resizing. **Rationale:** The Prop Editor already shows a stickman guide, but its current Normalize Size target is 96 world units against an approximately 940-unit standing figure; current artwork dimensions also vary widely. The approved Phase 19 addition replaces Normalize Size with a reversible **Size for Stage** preview: Small/Room/Big starts plus fine adjustment, a foreground 1:1 figure, and a floor guide. Artist chooses ordinary dimensions from asset intent; new placements use authored size. Individual Scenery resize commits on release, while group resize keeps its existing Keep/Cancel preview. Loading performs no automatic normalization. Ordinary Save and live-reference behavior remain, with no new copy/version prompts. Phase 19 user/editor verification remains pending. **Connections:** [Phase 10a Prop Scaling](../specs/phase_10a_prop_scaling.md), [Phase 19 Scenery, Backgrounds, and Surface Finishes](../plans/phase_19_scenery_backgrounds_surface_finishes.md), [approved Phase 19 UI](../specs/phase_19_scenery_backgrounds_ui_ux.md), `scripts/editors/prop/prop_editor.gd`, `scripts/editors/prop/prop_canvas.gd`, `scripts/editors/stickman/whole_stickman_preview.gd`.
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+11. **Size-aware artwork previews** — **Status:** Idea · **Suggested priority:** Low. **Intent:** Show a stickman silhouette or simple relative-size cue in artwork catalog previews so children can judge an asset before placing it. **Rationale:** Once asset dimensions are authored consistently, a size cue could reduce trial-and-error in the Stage without forcing objects to a fixed size. This depends on a settled Stage scale convention and should remain a browse-time hint, not an automatic resize. **Connections:** Stage-relative prop and scenery scale (backlog item 10), `scripts/editors/stage/stage_asset_browser.gd`, `scripts/shared/ui/asset_card.gd`.
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 ## Entry format
 
 For each feature, record: