Add SVG component support with runtime fixes

[bpc-oss]

Summary

This PR adds SVG component support to react-nodegui using QSvgWidget, and includes the runtime fixes needed to make the feature work reliably.

It covers:

• Svg root component plus exported helpers like Rect, Circle, Path, and SvgText
• inline SVG tree serialization
• src, content, and buffer loading paths
• mixed text / tspan handling inside SVG text nodes
• safe child move/reorder behavior in SVG trees
• a repo-local acceptance command: npm run verify:svg

Fixes #31.

Why this PR

There are already related attempts in #387, #388, and #389. Compared with those branches, this version also fixes the runtime issues that blocked a clean handoff:

• fixes unbound createInstance behavior for nested SVG elements
• removes the private @nodegui/nodegui/dist/... dependency
• adds SVG-specific text update handling in the reconciler
• fixes reorder semantics so moved SVG children are not duplicated
• codifies acceptance coverage in-repo instead of relying only on ad hoc smoke commands

Verification

Ran locally:

• npm run build
• npm run verify:svg

npm run verify:svg covers:

• root import smoke
• README helper shapes
• lowercase rect
• SvgText
• content / buffer / src
• adjacent text serialization
• mixed tspan serialization
• mixed text update after mount
• reorder / move behavior

Notes

• SVG text should use SvgText rather than the existing host Text component.
• Verification is now repo-local and repeatable, though it is still an acceptance harness rather than a full unit/integration test suite.

[woahwhattheheck]

A focused serialization correction from our preserved source packet: true-valued JSX attributes currently serialize as bare names, which is valid HTML boolean syntax but invalid XML attribute syntax for inline SVG. The existing escaped string path already converts true to "true". The suggestion keeps false/null omission and the rest of this implementation unchanged, preserving @bpc-oss's feature authorship. Source inspection only; I did not run Qt, TypeScript, or verify:svg. AI-assisted review.

Packet: https://github.com/woahwhattheheck/commons/tree/main/work/bounty-intake/nodegui31-svg-boolean-20261005-7ca6

[woahwhattheheck]

Use the existing quoted/escaped value path for true as well, so the output remains well-formed XML:

Suggested change

	result.push(value === true ? attributeName : `${attributeName}="${escapeAttribute(attributeValue)}"`);
	result.push(`${attributeName}="${escapeAttribute(attributeValue)}"`);