fix: pass streamSessionId when fetching live play URL

Require session id in getLivePlayURL and guard Monitor refresh
so play-url requests match the backend contract.

src/api/live.js

@@ -4,8 +4,10 @@ export function joinLive(dockId, payload = {}) {
   return request.post(`/v1/live/${dockId}/sessions`, payload)
 }
 
-export function getLivePlayURL(dockId) {
-  return request.get(`/v1/live/${dockId}/play-url`)
+export function getLivePlayURL(dockId, sessionId) {
+  return request.get(`/v1/live/${dockId}/play-url`, {
+    params: { streamSessionId: sessionId }
+  })
 }
 
 export function heartbeatLive(dockId, sessionId) {

src/composables/useMonitorLive.js

@@ -46,8 +46,8 @@ export function useMonitorLive({ getDockId, ui, getLivePlayer }) {
   }
 
   async function refreshPlayURL() {
-    if (!live.dockId) return
-    const play = await getLivePlayURL(live.dockId)
+    if (!live.dockId || !live.session?.id) return
+    const play = await getLivePlayURL(live.dockId, live.session.id)
     live.playUrl = play.playUrl || ''
   }