Preserve safe inline SVG icons during HTML-to-block conversion

[chubes4]

Problem

HTML-to-block conversion currently records inline SVG as fallback metadata and emits the surrounding CSS-addressable wrappers as empty group blocks. That preserves layout classes, but drops visible icon glyphs.

This is generic HTML behavior, not a Figma-specific rule. Figma exports are one reproducer because many icons arrive as inline SVG vectors inside styled wrappers.

Reproducer shape

<main>
  <div class="icon-wrapper">
    <div class="icon-vector">
      <svg viewBox="0 0 24 24" role="img" aria-label="Phone">
        <path d="M0 0h24v24H0z" fill="#a28b77" />
      </svg>
    </div>
  </div>
</main>

Current result keeps icon-wrapper / icon-vector groups but drops the svg, so the rendered icon disappears.

Desired behavior

Convert safe inline SVG/vector content into a WordPress-renderable representation without reintroducing raw fallback blocks.

Possible directions:

• Materialize sanitized SVG as an asset and emit core/image.
• Preserve sanitized inline SVG in a controlled block representation if Gutenberg accepts it safely.
• Keep diagnostics for unsafe or unsupported SVG, but avoid silent visual loss for safe icon glyphs.

Acceptance criteria

• Generic php-transformer contract covers safe inline SVG icon preservation without Figma-specific names.
• Existing fallback/core-html quality gates remain intact.
• Figma-origin fixtures with location/phone/clock/WhatsApp icons render visible glyphs after import.

Evidence

Local Fisiostetic fixture contains icons as inline SVG. Imported WordPress content keeps wrapper classes but has svg_count=0 and img_count=0; import diagnostics include inline SVG fallback records.

[chubes4]

Implemented on PR #43 in cd902b4 Preserve safe inline SVG icons.

Approach: safe inline SVG converts to generic core/image with a sanitized SVG data URI; unsafe SVG remains a fallback diagnostic. This keeps php-transformer agnostic to Figma and avoids reintroducing core/html blocks.

Local downstream Fisiostetic verification through SSI: saved post content now has img_count=16, svg_data_uri_count=32, core_html_blocks=0, fallback blocks 0, icon wrapper classes present, and no html_inline_svg_fallback mentions.