DUNGEONS-34: implement Webka local streaming app

Co-authored-by: multica-agent <github@multica.ai>

frontend/components/StreamVideo.vue

@@ -0,0 +1,18 @@
+<script setup lang="ts">
+const props = defineProps<{ stream: MediaStream | null; mirror?: boolean }>();
+const video = ref<HTMLVideoElement>();
+watch(
+  () => props.stream,
+  async (stream) => {
+    await nextTick();
+    if (video.value) {
+      video.value.srcObject = stream;
+      if (stream) void video.value.play().catch(() => {});
+    }
+  },
+  { immediate: true },
+);
+</script>
+<template>
+  <video ref="video" autoplay playsinline muted :class="{ mirrored: mirror }" />
+</template>