feat: add ChatStreamingBubble extracted streaming state component

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/ChatStreamingBubble.vue

@@ -0,0 +1,56 @@
+<script setup lang="ts">
+import { computed } from 'vue'
+import { useChatStore } from '@/stores/chat'
+import { useSettingsStore } from '@/stores/settings'
+import { renderMarkdown } from '@/utils/markdown'
+import ToolCallCard from '@/components/ToolCallCard.vue'
+import ToolConfirmCard from '@/components/ToolConfirmCard.vue'
+
+const store = useChatStore()
+const settingsStore = useSettingsStore()
+
+const streamingRendered = computed(() => {
+  if (!store.streamingContent) return ''
+  return renderMarkdown(store.streamingContent)
+})
+</script>
+
+<template>
+  <div class="chat-message role-assistant">
+    <div class="message-bubble streaming-bubble">
+      <div class="message-header">
+        <span class="role-label">{{ settingsStore.assistantName }}</span>
+      </div>
+      <div v-if="store.streamingToolCalls.length" class="streaming-tool-calls">
+        <ToolCallCard
+          v-for="(tc, i) in store.streamingToolCalls"
+          :key="i"
+          :tool-call="tc"
+        />
+      </div>
+      <ToolConfirmCard
+        v-if="store.streamingPendingTool"
+        :pending-tool="store.streamingPendingTool"
+        @accept="store.confirmTool(true)"
+        @decline="store.confirmTool(false)"
+      />
+      <div v-if="store.streamingStatus" class="streaming-status-line">
+        <span class="streaming-status-dot"></span>
+        {{ store.streamingStatus }}
+      </div>
+      <details
+        v-if="store.streamingThinking"
+        class="thinking-block"
+        :open="!store.streamingContent"
+      >
+        <summary class="thinking-summary">Reasoning</summary>
+        <pre class="thinking-text">{{ store.streamingThinking }}</pre>
+      </details>
+      <div class="message-content prose" v-html="streamingRendered"></div>
+      <span
+        v-if="!store.streamingStatus && !store.streamingThinking && !store.streamingContent"
+        class="typing-indicator"
+      ></span>
+    </div>
+  </div>
+</template>