♻️(frontend) starting a bit more structured frontend app

the idea is to use react aria, panda-css, react query and wouter as a
base, in addition to livekit react components

this is still mostly wip but it's usable:

- homepage shows a login link to create a room
- before joining a room you are asked to configure your audio/video/user
name
- note that if you directly go to a a conference url it creates it even
if you are not logged in… very secured!

src/frontend/postcss.config.cjs

@@ -0,0 +1,5 @@
+module.exports = {
+  plugins: {
+    '@pandacss/dev/postcss': {},
+  },
+}