✨(frontend) add persistence for video publishing resolution setting

Implement user choice persistence for video publishing resolution
configuration to maintain user preferences across sessions.

Stores selected video resolution in user settings, ensuring consistent
video quality preferences without requiring reconfiguration on each
visit.

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

@@ -12,6 +12,7 @@ import {
   RoomOptions,
   supportsAdaptiveStream,
   supportsDynacast,
+  VideoPresets,
 } from 'livekit-client'
 import { keys } from '@/api/queryKeys'
 import { queryClient } from '@/api/queryClient'
@@ -98,6 +99,9 @@ export const Conference = ({
       },
       videoCaptureDefaults: {
         deviceId: userConfig.videoDeviceId ?? undefined,
+        resolution: userConfig.videoPublishResolution
+          ? VideoPresets[userConfig.videoPublishResolution].resolution
+          : undefined,
       },
       audioCaptureDefaults: {
         deviceId: userConfig.audioDeviceId ?? undefined,
@@ -109,6 +113,7 @@ export const Conference = ({
     // do not rely on the userConfig object directly as its reference may change on every render
   }, [
     userConfig.videoDeviceId,
+    userConfig.videoPublishResolution,
     userConfig.audioDeviceId,
     userConfig.audioOutputDeviceId,
     isAdaptiveStreamSupported,

src/frontend/src/features/rooms/livekit/hooks/usePersistentUserChoices.ts

@@ -1,5 +1,6 @@
 import { useSnapshot } from 'valtio'
 import { userChoicesStore } from '@/stores/userChoices'
+import type { VideoResolution } from '@/stores/userChoices'
 import { ProcessorSerialized } from '@/features/rooms/livekit/components/blur'
 
 export function usePersistentUserChoices() {
@@ -22,6 +23,9 @@ export function usePersistentUserChoices() {
     saveVideoInputDeviceId: (deviceId: string) => {
       userChoicesStore.videoDeviceId = deviceId
     },
+    saveVideoPublishResolution: (resolution: VideoResolution) => {
+      userChoicesStore.videoPublishResolution = resolution
+    },
     saveUsername: (username: string) => {
       userChoicesStore.username = username
     },

src/frontend/src/stores/userChoices.ts

@@ -6,16 +6,20 @@ import {
   LocalUserChoices as LocalUserChoicesLK,
 } from '@livekit/components-core'
 
+export type VideoResolution = 'h720' | 'h360' | 'h180'
+
 export type LocalUserChoices = LocalUserChoicesLK & {
   processorSerialized?: ProcessorSerialized
   noiseReductionEnabled?: boolean
   audioOutputDeviceId?: string
+  videoPublishResolution?: VideoResolution
 }
 
 function getUserChoicesState(): LocalUserChoices {
   return {
     noiseReductionEnabled: false,
     audioOutputDeviceId: 'default', // Use 'default' to match LiveKit's standard device selection behavior
+    videoPublishResolution: 'h720',
     ...loadUserChoices(),
   }
 }