fix: briefing refresh — weather not populated + workspace conv bleed

Two bugs:

1. Manual 'Refresh' button didn't refresh weather/RSS before compiling.
   The daily scheduler calls refresh_all_feeds + refresh_location_cache
   before run_compilation; the manual trigger route called run_compilation
   directly, reading a stale cache. Manual trigger now mirrors the
   scheduler: refresh feeds and all configured weather locations first.

2. Navigating to WorkspaceView during a long briefing compilation caused
   the workspace chat to show the briefing content. triggerNow awaits
   ~30-60s; on completion it called loadAll() → chatStore.fetchConversation
   which overwrote the workspace's currentConversation in the shared store.
   Fixed with a _mounted flag — all post-async state writes in BriefingView
   are now guarded so they no-op if the component has been unmounted.

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

frontend/src/views/BriefingView.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { ref, computed, onMounted, watch, nextTick } from 'vue'
+import { ref, computed, onMounted, onUnmounted, watch, nextTick } from 'vue'
 import { useBackgroundRefresh } from '@/composables/useBackgroundRefresh'
 import { useVoiceRecorder } from '@/composables/useVoiceRecorder'
 import { useVoiceAudio } from '@/composables/useVoiceAudio'
@@ -150,10 +150,10 @@ watch(selectedConvId, async (id) => {
 
 // Refresh messages after streaming ends
 watch(() => chatStore.streaming, async (streaming) => {
-  if (!streaming && selectedConvId.value === todayConvId.value && todayConvId.value) {
+  if (!streaming && _mounted && selectedConvId.value === todayConvId.value && todayConvId.value) {
     const today = await getBriefingToday().catch(() => null)
-    if (today) messages.value = today.messages
-    scrollToBottom()
+    if (_mounted && today) messages.value = today.messages
+    if (_mounted) scrollToBottom()
   }
 })
 
@@ -239,9 +239,10 @@ async function triggerNow() {
   triggering.value = true
   try {
     await triggerBriefingSlot('compilation')
-    await loadAll()
+    // Guard: user may have navigated away during the long compilation
+    if (_mounted) await loadAll()
   } finally {
-    triggering.value = false
+    if (_mounted) triggering.value = false
   }
 }
 
@@ -365,6 +366,9 @@ useBackgroundRefresh(
   () => !chatStore.streaming && isToday.value && !!todayConvId.value,
 )
 
+let _mounted = true
+onUnmounted(() => { _mounted = false })
+
 onMounted(async () => {
   await checkSetup()
   if (!showWizard.value) await loadAll()