wave E stage 2: renderSvg goes native-first - resvg in-process

Visual-maker SVGs never execute script, so a browser added nothing but a
process. resvg rasterizes in-process now (white background and fitTo
width mirror the old Chrome-page semantics; svgViewport unchanged,
quirks included for parity). The old Chrome path stays verbatim as the
fallback for exotic-SVG parse failures - it was the only path before,
so nothing regresses.

The resvg binary (4MB per platform, one per build) rides the standalone
via the same tracing pattern. Gates 1519/1519; native path pinned
against real SVGs (intrinsic size, viewBox-only 900 default, opts
override, system-font text).

package.json

@@ -22,6 +22,7 @@
 		"@earendil-works/pi-ai": "1.0.2",
 		"@mozilla/readability": "^0.6.0",
 		"@radix-ui/react-use-controllable-state": "^1.2.6",
+		"@resvg/resvg-js": "^2.6.2",
 		"@rive-app/react-webgl2": "^4.32.1",
 		"@streamdown/cjk": "^1.0.3",
 		"@streamdown/code": "^1.1.1",