v0.3.4

This is a corrective maintenance patch on top of 0.3.3.

It normalizes the documentation project version in Documentation/guides.xml so it matches the extension version, and adds a dedicated docs-render CI job so the rendered documentation is verified on every change. The functional fixes shipped in 0.3.3 — the crash fix, backend icons, and dashboard widgets — remain in place; this release only tidies the documentation and CI plumbing around them.

Being an additive 0.x patch, downstream ^0.3 version constraints pick it up automatically with no code changes required.