Switch icons from a webfont to self-hosted SVG masks — the webfont was the actual problem

Self-hosting Font Awesome's font files (previous commit) didn't fix it either: every icon in the picker still failed identically. That rules out CDN/network blocking specifically and points to something in the browser blocking custom webfont loading altogether regardless of origin (common with strict anti-fingerprinting protection, e.g. Brave's font blocking or certain privacy extensions — @font-face loading is a well-known fingerprinting vector).

Replaced the whole mechanism: each of the 258 curated icons is now a real downloaded SVG file (static/icons/*.svg, sourced from Font Awesome 5 Free's official SVG package) displayed via CSS mask-image (.icon-svg in style.css) instead of a font glyph. A masked SVG isn't a font resource at all, so it isn't subject to webfont-blocking — and it still colors via the existing "color" style property (background-color:currentColor) and sizes via font-size (1em), so no change to how the widget's other controls work.

The "Icône" widget now stores just the icon's slug (e.g. "trophy") in a dedicated attribute instead of a full CSS class string, rendered by a new special_render (render_icone.py). Updated the add-gallery and the properties-panel picker modal to use the same mask technique for their previews, and element_add.py to validate the slug against the curated list. Removed the now-unused self-hosted Font Awesome CSS/webfont files and the <link> tags — no font dependency left for icons at all.

Verified end to end (gallery renders with real SVG previews, simulated add creates a correctly-attributed element, the SVG file is actually served, the per-element picker reflects the current icon). Full suite green (89).

static/icons/bomb.svg

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+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!-- Font Awesome Free 5.15.4 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) --><path d="M440.5 88.5l-52 52L415 167c9.4 9.4 9.4 24.6 0 33.9l-17.4 17.4c11.8 26.1 18.4 55.1 18.4 85.6 0 114.9-93.1 208-208 208S0 418.9 0 304 93.1 96 208 96c30.5 0 59.5 6.6 85.6 18.4L311 97c9.4-9.4 24.6-9.4 33.9 0l26.5 26.5 52-52 17.1 17zM500 60h-24c-6.6 0-12 5.4-12 12s5.4 12 12 12h24c6.6 0 12-5.4 12-12s-5.4-12-12-12zM440 0c-6.6 0-12 5.4-12 12v24c0 6.6 5.4 12 12 12s12-5.4 12-12V12c0-6.6-5.4-12-12-12zm33.9 55l17-17c4.7-4.7 4.7-12.3 0-17-4.7-4.7-12.3-4.7-17 0l-17 17c-4.7 4.7-4.7 12.3 0 17 4.8 4.7 12.4 4.7 17 0zm-67.8 0c4.7 4.7 12.3 4.7 17 0 4.7-4.7 4.7-12.3 0-17l-17-17c-4.7-4.7-12.3-4.7-17 0-4.7 4.7-4.7 12.3 0 17l17 17zm67.8 34c-4.7-4.7-12.3-4.7-17 0-4.7 4.7-4.7 12.3 0 17l17 17c4.7 4.7 12.3 4.7 17 0 4.7-4.7 4.7-12.3 0-17l-17-17zM112 272c0-35.3 28.7-64 64-64 8.8 0 16-7.2 16-16s-7.2-16-16-16c-52.9 0-96 43.1-96 96 0 8.8 7.2 16 16 16s16-7.2 16-16z"/></svg>