feat(runtime): add M1 scene persistence, undo/redo and hotkeys

- load .forge.ron through bevy_forge_core into the live ECS (3D components)
- Ctrl+S syncs and saves the document; custom components are preserved
- transform undo/redo for inspector sliders and gizmo drags (Ctrl+Z/Y)
- F focus, Delete subtree, Ctrl+D duplicate; camera subtrees are guarded
- 66 runtime tests; workspace 412 passed; garden demo docs/screenshots

crates/bevy_forge_runtime/Cargo.toml

@@ -7,9 +7,10 @@ license.workspace = true
 authors.workspace = true
 repository.workspace = true
 publish = false
-description = "Live in-game scene editor plugin for Bevy 0.20 (M0 spike)"
+description = "Live in-game scene editor plugin for Bevy 0.20 (M0/M1)"
 
 [dependencies]
+bevy_forge_core = { path = "../bevy_forge_core" }
 # Frozen M0 feature set. Do not add `tonemapping_luts` (ktx2/zstd) — cameras use
 # `Tonemapping::AcesFitted` instead of the LUT-based default.
 bevy = { version = "0.20", default-features = false, features = [