feat: weather precip/wind, dashboard mic, remove global voice overlay

- WeatherCard: show precipitation (mm) and max wind speed per forecast day
- DashboardChatInput: add PTT mic button (transcribe-to-input, voice-gated)
- Remove global VoiceOverlay floating button and Space PTT shortcut from
  App.vue — inline mic buttons in chat/briefing/dashboard are the right UX;
  global overlay had focus/latency/context issues

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

frontend/src/App.vue

@@ -3,7 +3,6 @@ import { onMounted, onUnmounted, ref, watch } from "vue";
 import { useRouter } from "vue-router";
 import AppHeader from "@/components/AppHeader.vue";
 import ToastNotification from "@/components/ToastNotification.vue";
-import VoiceOverlay from "@/components/VoiceOverlay.vue";
 import { useTheme } from "@/composables/useTheme";
 import { useShortcuts } from "@/composables/useShortcuts";
 import { useAuthStore } from "@/stores/auth";
@@ -48,21 +47,9 @@ function clearPrefix() {
   prefixTimeout = null;
 }
 
-let spaceHeld = false;
-
 function onGlobalKeydown(e: KeyboardEvent) {
   if (!authStore.isAuthenticated) return;
 
-  // Space — PTT start (only when not typing, no modifiers, no repeat)
-  if (e.key === " " && !isInputActive() && !e.ctrlKey && !e.metaKey && !e.altKey && !e.repeat) {
-    e.preventDefault();
-    if (!spaceHeld) {
-      spaceHeld = true;
-      document.dispatchEvent(new CustomEvent("voice:ptt-toggle"));
-    }
-    return;
-  }
-
   // ? — toggle shortcuts overlay (only when not typing)
   if (e.key === "?" && !isInputActive() && !e.ctrlKey && !e.metaKey) {
     toggleShortcuts();
@@ -135,16 +122,8 @@ function onGlobalKeydown(e: KeyboardEvent) {
   }
 }
 
-function onGlobalKeyup(e: KeyboardEvent) {
-  if (e.key === " " && spaceHeld) {
-    spaceHeld = false;
-    document.dispatchEvent(new CustomEvent("voice:ptt-toggle"));
-  }
-}
-
 onMounted(async () => {
   document.addEventListener("keydown", onGlobalKeydown);
-  document.addEventListener("keyup", onGlobalKeyup);
   await authStore.checkAuth();
   if (authStore.isAuthenticated) {
     startAppServices();
@@ -170,7 +149,6 @@ watch(
 
 onUnmounted(() => {
   document.removeEventListener("keydown", onGlobalKeydown);
-  document.removeEventListener("keyup", onGlobalKeyup);
   stopAppServices();
 });
 </script>
@@ -186,9 +164,6 @@ onUnmounted(() => {
       <footer class="app-footer">v{{ appVersion }}</footer>
     </div>
 
-    <!-- Global voice PTT overlay -->
-    <VoiceOverlay />
-
     <!-- Keyboard shortcuts overlay -->
     <Transition name="shortcuts-fade">
       <div v-if="showShortcuts" class="shortcuts-overlay" @click.self="closeShortcuts">