Migrate cotton to Python + template tag shims

common/icons.py

@@ -0,0 +1,27 @@
+import functools
+from pathlib import Path
+
+_ICON_DIR = (
+    Path(__file__).resolve().parent.parent / "games" / "templates" / "cotton" / "icon"
+)
+
+
+@functools.lru_cache(maxsize=1)
+def _load_icons() -> dict[str, str]:
+    """Load all icon HTML files into a dict.
+
+    Cached so files are read once per process lifetime.
+    Delegation (e.g. nintendo-3ds -> nintendo) is handled by
+    both files containing identical SVG content.
+    """
+    icons: dict[str, str] = {}
+    for filepath in _ICON_DIR.glob("*.html"):
+        name = filepath.stem
+        icons[name] = filepath.read_text()
+    return icons
+
+
+def get_icon(name: str) -> str:
+    """Return the HTML for an icon by name. Falls back to 'unspecified'."""
+    icons = _load_icons()
+    return icons.get(name, icons.get("unspecified", ""))