feat(editor): Scene Editor Orchestrator with dockspace, menus, console, profiler (RF6.6)

[LyeZinho]

Summary

• Split SceneEditor from a 197-line inline header into clean .hpp/.cpp (RF6.3)
• Added ImGui Dockspace layout with DockBuilder (Hierarchy left, Inspector right, Viewport center, Asset Browser + Console + Profiler bottom)
• Main menu bar: File (New/Save/Open/Exit), Edit (Undo/Redo), View (toggle panels)
• Status bar: scene path, dirty flag (Modified/Saved), undo stack depth
• Keyboard shortcuts: Ctrl+S save, Ctrl+Z undo, Ctrl+Shift+Z redo, Ctrl+Y redo
• Console and Profiler window integration as editor members
• Asset drop handling: drag asset from browser → creates entity with Position2D + Sprite
• Undo-wrapped scene operations (New Scene clears undo stack, asset drop wraps in undo)

Closes

Closes #80

Related

Continues the M1 editor panel refactoring series after #76 (Hierarchy), #78 (Scene Viewport), #79 (Asset Browser), #77 (Inspector).