Character portrait

Crop-and-zoom picture editor on the Concept page, stored (re-encoded to a
256 px WebP data URL) inside the character; shown on the sheet header, in
the lobby player bar and as token icon on the map.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HJhXuLD2Z6hv3Wqeq9UL9K

frontend/src/PaperSheet.jsx

@@ -110,6 +110,7 @@ export default function PaperSheet({ data, baseRules, tools, bare, onRoll }) {
         <section className="paper">
           <header className="phead">
             <div className="pname">{name}</div>
+            {ch.portrait && <img className="pportrait" src={ch.portrait} alt="" />}
             <div className="pbrand">Arcane Wasteland<span>Character sheet</span></div>
           </header>
           <div className="pfields">