♻️(frontend) refactor the username storage

Create a new dedicated store for user choices, starting with the
username, to decouple this part from any LiveKit elements. This is
better for tree-shaking, and depending on LiveKit for storing the
username brings no real value.

The refactoring will be continued later for the other user choices
that can be persisted.

src/frontend/src/features/rooms/components/Conference.tsx

@@ -36,6 +36,7 @@ import { PictureInPictureConference } from '@/features/pip/components/PictureInP
 import { notifyAutoMutedOnJoin } from '@/features/notifications/utils'
 import { useSnapshot } from 'valtio'
 import { userPreferencesStore } from '@/stores/userPreferences'
+import { userStore } from '@/stores/user'
 
 export const Conference = ({
   roomId,
@@ -53,6 +54,8 @@ export const Conference = ({
     userChoices: LocalUserChoices
   }
 
+  const { username } = useSnapshot(userStore)
+
   useEffect(() => {
     posthog.capture('visit-room', { slug: roomId })
   }, [roomId, posthog])
@@ -83,10 +86,10 @@ export const Conference = ({
     queryFn: () =>
       fetchRoom({
         roomId: roomId as string,
-        username: userConfig.username,
+        username: username,
       }).catch((error) => {
         if (error.statusCode == '404') {
-          createRoom({ slug: roomId, username: userConfig.username })
+          createRoom({ slug: roomId, username })
         }
       }),
     retry: false,

src/frontend/src/features/rooms/components/Join.tsx

@@ -42,12 +42,13 @@ import {
   saveAudioInputDeviceId,
   saveAudioInputEnabled,
   saveAudioOutputDeviceId,
-  saveUsername,
   saveVideoInputDeviceId,
   saveVideoInputEnabled,
   userChoicesStore,
 } from '@/stores/userChoices'
 
+import { saveUsername, userStore } from '@/stores/user'
+
 import { useCannotUseDevice } from '../livekit/hooks/useCannotUseDevice'
 import { useSnapshot } from 'valtio'
 
@@ -121,9 +122,10 @@ export const Join = ({
     audioOutputDeviceId,
     videoDeviceId,
     processorConfig,
-    username,
   } = useSnapshot(userChoicesStore)
 
+  const { username } = useSnapshot(userStore)
+
   const initialUserChoices = useRef<LocalUserChoices | null>(null)
 
   if (initialUserChoices.current === null) {
@@ -134,7 +136,6 @@ export const Join = ({
       audioOutputDeviceId,
       videoDeviceId,
       processorConfig,
-      username,
     }
   }