feat(backend): add SIMPLE_STREAMING WebRTC control-path streaming

Backend/media/config.ts

@@ -25,10 +25,29 @@ const parsePositiveNumber = (value: string | undefined): number | null => {
   return parsed;
 };
 
+export const parseFeatureFlag = (value: string | undefined, defaultValue: boolean): boolean => {
+  if (value === undefined) {
+    return defaultValue;
+  }
+
+  const normalized = value.trim().toLowerCase();
+  if (['1', 'true', 'yes', 'on'].includes(normalized)) {
+    return true;
+  }
+  if (['0', 'false', 'no', 'off'].includes(normalized)) {
+    return false;
+  }
+  return defaultValue;
+};
+
 export const mediaMode: MediaMode = parseMediaMode(process.env.MEDIA_MODE);
+export const simpleStreamingEnabled = parseFeatureFlag(process.env.SIMPLE_STREAMING, false);
+export const streamRecordingEnabled = parseFeatureFlag(process.env.STREAM_RECORDINGS_ENABLED, false);
 
 export const mediaConfig = {
   mode: mediaMode,
+  simpleStreamingEnabled,
+  streamRecordingEnabled,
   turn: {
     urls: parseCsv(process.env.TURN_URLS),
     username: process.env.TURN_USERNAME ?? '',
@@ -40,4 +59,3 @@ export const mediaConfig = {
     maxSubscribersPerRoom: parsePositiveNumber(process.env.MEDIA_MAX_SUBSCRIBERS_PER_ROOM),
   },
 };
-

Backend/media/providers/mock.ts

@@ -37,6 +37,8 @@ export class MockMediaProvider implements MediaProvider {
   name = 'mock';
 
   async createSession(input: MediaSessionCreateInput): Promise<MediaSessionCreateResult> {
+    // SIMPLE_STREAMING bypasses provider-backed transport at runtime. This metadata
+    // path is kept only for legacy endpoints and backwards compatibility.
     const mediaSessionId = `mock_${input.streamSessionId}`;
     const baseUrl = getBaseUrl();
 

Backend/media/service.ts

@@ -1,5 +1,6 @@
+import { simpleStreamingEnabled } from './config';
 import { MockMediaProvider } from './providers/mock';
-import type { MediaProvider } from './types';
+import type { MediaProvider, MediaSessionCreateInput, MediaSessionCreateResult } from './types';
 
 const providerName = (process.env.MEDIA_PROVIDER ?? 'mock').toLowerCase();
 
@@ -13,3 +14,14 @@ const createProvider = (): MediaProvider => {
 };
 
 export const mediaProvider = createProvider();
+export const mediaProviderRuntimeEnabled = !simpleStreamingEnabled;
+
+export const createLiveMediaSession = async (
+  input: MediaSessionCreateInput,
+): Promise<MediaSessionCreateResult | null> => {
+  if (!mediaProviderRuntimeEnabled) {
+    return null;
+  }
+
+  return mediaProvider.createSession(input);
+};

Backend/media/sfu/service.ts

@@ -1,8 +1,12 @@
-import { mediaMode } from '../config';
+import { mediaMode, simpleStreamingEnabled } from '../config';
 import { NoopSfuService } from './noop';
 import type { SfuService } from './types';
 
 const createSfuService = (): SfuService | null => {
+  if (simpleStreamingEnabled) {
+    return null;
+  }
+
   if (mediaMode !== 'single_server_sfu') {
     return null;
   }
@@ -11,4 +15,3 @@ const createSfuService = (): SfuService | null => {
 };
 
 export const sfuService = createSfuService();
-