[0.2.0] DenyExtraGraphics overlay suppression on Quick canvas

[cursor]

Parent: #356

Harvest from gh-143 tst_overlayrenderingtest.cpp::denyExtraGraphicsSuppressesOverlays.

Widgets suppressed all overlay providers when PDFRenderer::DenyExtraGraphics was set. The Quick product path needs an equivalent presentation gate so tool/page overlays can be suppressed without invalidating admitted page surfaces.

Acceptance

• Overlay suppression does not call PageSurfaceCoordinator::requestSurfaces
• Suppressed state is observable from LoupeCanvasItem / overlay frame (empty or gated primitives)
• Test ported from [Interaction quality] Render selections, guides, and preflight markers as independent overlays #143 oracle

Reference

• docs/handoffs/0.2.0-gh143-parity-checklist.md