Introduce a Chrome-DevTools-style ECS inspector in the UI library. The
headless core (ComponentReflector + EcsInspector) enumerates the store's
entities grouped by archetype, reflects a selected entity's components and
fields, and writes simple scalar edits (number/bool/enum) back through a
generic AddComponent — all unit-tested without a GPU. The Myra overlay
(EcsInspectorUi + InspectorSystems) adds a side panel with an
archetypes -> entities -> fields tree, an editable field view, a
world-pick mode with a selection highlight, and a renderer performance
tab; wired via scene.UseInspector(renderer), toggled with F1.
The UI library now references Graphics (for picking, renderer timings and
Transform2D/Sprite). Docs updated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
