feat: add neon color picker for wallet management

- Replace muted Tailwind palette with 16-color neon palette
- Add clickable color dot in sidebar that opens a popup swatch grid
- Allow color override for all wallets (including embedded)
- Fix getColorForWallet to respect localStorage override
- Fix duplicate renameWallet in wallets.js
- Update Dockerfile to serve ESM modules via nginx

Dockerfile

@@ -1,4 +1,7 @@
 FROM nginx:alpine
 COPY index.html /usr/share/nginx/html/index.html
+COPY wallets.js /usr/share/nginx/html/wallets.js
+COPY verifier.js /usr/share/nginx/html/verifier.js
+COPY stream.js /usr/share/nginx/html/stream.js
 COPY default.conf /etc/nginx/conf.d/default.conf
 EXPOSE 80