Fix Canvas renderer options, SVG loading, and pointer event semantics

[jonobr1]

Canvas aliases currently fail at construction, SVG loading ignores shallow and leaks lifecycle ownership, and pointer dispatch disagrees with Two.js coordinates and nested scene order. This change fixes all three open bug issues and documents the resulting behavior.

• Normalize all six renderer spellings. Update width, height, and autostart in place; warn in development when type, fullscreen, ratio, overdraw, or smoothing changes without a key remount. Clean up fullscreen resize listeners and owned body styles. Apply SVG viewBox as an attribute.
• Load URL SVGs with abortable fetch, validate inline documents, prevent stale results, implement shallow imports, and release owned imports without removing JSX children or borrowed effects. Preserve imported/JSX ordering across reorders and use current callbacks without reloading.
• Use renderer world coordinates throughout, SVG screen transforms for viewport scaling, and upstream leaf traversal for complete scene order. Bubble through actual ancestry, exclude invisible/clipped/unpainted geometry, and respect masks. Add per-pointer capture that survives callback updates, deterministic hover transitions, and missed notifications only for complete empty primary presses.

Behavior changes: event.point now uses top-left renderer world coordinates; Group events target the actual leaf; onPointerMissed requires an empty primary down/up sequence. SVG shallow removes only the imported top-level group and its root transforms. Constructor options require a React key remount. Details and dragging examples are in the README.

Validation:

• 242 tests passed across 21 files (45 more than baseline).
• npm run lint: passed without warnings.
• npx tsc -b, npm run build:lib, and npm run build:docs: passed. Docs build retains its large-chunk advisory.
• Executed tests/browser/ in the in-app browser using real SVG, Canvas, and WebGL: all six renderer spellings passed CSS coordinate, masked-event, and shallow-import checks. Native dragging verified capture, movement, bubbling, and release outside each renderer.

Fixes #8
Fixes #32
Fixes #34

[Copilot]

🟡 Changes recommended

Unpainted non-Path objects can intercept events, and imported SVG renderer resources are not fully released.

2 open findings

• Exclude unpainted shapes from hit testing · New
• Release renderer resources when cleaning up imported SVG objects · New

What changed in this PR

Fixes Canvas options, SVG loading lifecycle, and pointer-event semantics across renderers.

Changes:

• Normalizes renderer aliases and manages mutable/immutable Canvas options.
• Adds abortable SVG loading, shallow imports, ownership cleanup, and stable ordering.
• Reworks coordinates, hit testing, bubbling, pointer capture, and regression coverage.

File	Description
lib/​Provider.tsx	Updates Canvas lifecycle and event dispatch.
lib/​Events.ts	Implements coordinates, hit testing, and capture APIs.
lib/​SVG.tsx	Reworks SVG loading and ownership.
lib/​useTwoObject.ts	Preserves registration across callback updates.
README.md	Documents updated behavior.
tests/​canvasOptions.test.tsx	Tests Canvas options.
tests/​eventSemantics.test.tsx	Tests pointer semantics.
tests/​events.test.tsx	Updates event utility coverage.
tests/​svgLifecycle.test.tsx	Tests SVG lifecycle behavior.
tests/​browser/​index.html	Adds browser harness UI.
tests/​browser/​regressions.tsx	Adds real-renderer regression checks.

🧠 Review effort: Balanced

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