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).

screens/rendering/render_element_html.py

@@ -14,6 +14,7 @@ from .render_repeater import _render_repeater
 from .render_jauge import _render_jauge
 from .render_overlay import _render_overlay
 from .render_onglets import _render_onglets
+from .render_icone import _render_icone
 from .resolve_bound_row import _resolve_bound_row_ctx
 
 
@@ -50,6 +51,8 @@ def render_element_html(el, slug=None, children_map=None, ctx=None, parent_flex_
         return _render_overlay(el, meta, slug, children_map, ctx, parent_flex_direction)
     if special == "onglets":
         return _render_onglets(el, meta, slug, children_map, ctx, parent_flex_direction)
+    if special == "icone":
+        return _render_icone(el, meta, slug, children_map, ctx, parent_flex_direction)
 
     tag = meta.get("tag")
     if tag is None:  # widget à balise dynamique (ex: "titre" -> h1/h2/h3)