feat: unify voice PTT across briefing and chat views

- ChatView: add PTT mic button in input bar (hold to speak → transcribe → send)
- BriefingView: restyle input bar to match ChatView (floating pill, circle send)
- BriefingView: move listen/mic controls into input bar, remove from header
- BriefingView: consistent icon-button style for speaker/mic matching ChatView

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

frontend/src/views/ChatView.vue

@@ -3,8 +3,9 @@ import { onMounted, onUnmounted, ref, computed, watch, nextTick } from "vue";
 import { useRoute, useRouter } from "vue-router";
 import { useChatStore } from "@/stores/chat";
 import { useSettingsStore } from "@/stores/settings";
-import { apiGet } from "@/api/client";
+import { apiGet, getVoiceStatus, transcribeAudio } from "@/api/client";
 import { renderMarkdown } from "@/utils/markdown";
+import { useVoiceRecorder } from "@/composables/useVoiceRecorder";
 import ChatMessage from "@/components/ChatMessage.vue";
 import ToolCallCard from "@/components/ToolCallCard.vue";
 import ToolConfirmCard from "@/components/ToolConfirmCard.vue";
@@ -22,6 +23,38 @@ const sending = ref(false);
 const summarizing = ref(false);
 const sidebarOpen = ref(false);
 
+// Voice PTT
+const voiceEnabled = ref(false);
+const transcribingVoice = ref(false);
+const recorder = useVoiceRecorder();
+
+async function checkVoice() {
+  try {
+    const status = await getVoiceStatus();
+    voiceEnabled.value = status.enabled && status.stt;
+  } catch { /* voice absent */ }
+}
+
+async function startPtt() {
+  if (!voiceEnabled.value || recorder.recording.value) return;
+  await recorder.startRecording();
+}
+
+async function stopPtt() {
+  if (!recorder.recording.value) return;
+  transcribingVoice.value = true;
+  try {
+    const blob = await recorder.stopRecording();
+    const { transcript } = await transcribeAudio(blob);
+    if (transcript.trim()) {
+      messageInput.value = transcript.trim();
+      autoResize();
+      await sendMessage();
+    }
+  } catch { /* silent */ }
+  finally { transcribingVoice.value = false; }
+}
+
 // Research modal state
 const showResearchModal = ref(false);
 const researchTopic = ref("");
@@ -145,7 +178,7 @@ const inputPlaceholder = computed(() => {
 
 onMounted(async () => {
   document.addEventListener("keydown", onGlobalKeydown);
-  await Promise.all([store.fetchConversations(), loadProjects()]);
+  await Promise.all([store.fetchConversations(), loadProjects(), checkVoice()]);
   if (convId.value) {
     if (store.currentConversation?.id !== convId.value) {
       await store.fetchConversation(convId.value);
@@ -847,6 +880,27 @@ onUnmounted(() => {
               </div>
             </div>
 
+            <!-- Mic PTT button -->
+            <button
+              v-if="voiceEnabled && recorder.isSupported"
+              class="btn-attach btn-mic-ptt"
+              :class="{ 'mic-recording': recorder.recording.value, 'mic-transcribing': transcribingVoice }"
+              @mousedown.prevent="startPtt"
+              @mouseup.prevent="stopPtt"
+              @touchstart.prevent="startPtt"
+              @touchend.prevent="stopPtt"
+              :disabled="transcribingVoice || !store.chatReady"
+              :title="recorder.recording.value ? 'Release to send' : 'Hold to speak'"
+              aria-label="Push to talk"
+            >
+              <svg v-if="!transcribingVoice" width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
+                <path d="M12 14c1.66 0 3-1.34 3-3V5c0-1.66-1.34-3-3-3S9 3.34 9 5v6c0 1.66 1.34 3 3 3zm-1-9c0-.55.45-1 1-1s1 .45 1 1v6c0 .55-.45 1-1 1s-1-.45-1-1V5zm6 6c0 2.76-2.24 5-5 5s-5-2.24-5-5H5c0 3.53 2.61 6.43 6 6.92V21h2v-3.08c3.39-.49 6-3.39 6-6.92h-2z"/>
+              </svg>
+              <svg v-else width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
+                <path d="M12 4V1L8 5l4 4V6c3.31 0 6 2.69 6 6 0 1.01-.25 1.97-.7 2.8l1.46 1.46C19.54 15.03 20 13.57 20 12c0-4.42-3.58-8-8-8zm0 14c-3.31 0-6-2.69-6-6 0-1.01.25-1.97.7-2.8L5.24 7.74C4.46 8.97 4 10.43 4 12c0 4.42 3.58 8 8 8v3l4-4-4-4v3z"/>
+              </svg>
+            </button>
+
             <textarea
               ref="inputEl"
               v-model="messageInput"
@@ -1626,6 +1680,25 @@ details[open] .thinking-summary::before {
 .input-area textarea:disabled {
   opacity: 0.5;
 }
+.btn-mic-ptt {
+  touch-action: none;
+  user-select: none;
+  transition: color 0.15s, opacity 0.15s;
+}
+.btn-mic-ptt.mic-recording {
+  color: #ef4444 !important;
+  opacity: 1 !important;
+  animation: mic-pulse 0.8s ease-in-out infinite;
+}
+.btn-mic-ptt.mic-transcribing {
+  color: var(--color-primary) !important;
+  opacity: 0.7 !important;
+}
+@keyframes mic-pulse {
+  0%, 100% { opacity: 0.7; }
+  50% { opacity: 1; }
+}
+
 .btn-send {
   width: 34px;
   min-width: 34px;