feat: daily briefing frontend — view, setup wizard, settings tab, nav

- BriefingView: soft chat UI with conversation history dropdown, SSE
  streaming via chat store, manual refresh trigger, today/past conv toggle
- BriefingSetupWizard: 4-step first-time setup overlay (welcome →
  locations → office days → RSS feeds)
- SettingsView: Briefing tab with enable toggle, location geocoding,
  office day picker, slot toggles, RSS feed management, notifications
- AppHeader + router: /briefing route and nav link (desktop + mobile)
- client.ts: briefing types and API functions (config, feeds, convs,
  geocode, trigger)

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

frontend/src/api/client.ts

@@ -300,6 +300,122 @@ export function apiSSEStream(
   return { close: () => controller.abort(), done };
 }
 
+// ---------------------------------------------------------------------------
+// Briefing
+// ---------------------------------------------------------------------------
+
+export interface BriefingLocation {
+  label: string;
+  address: string;
+  lat?: number;
+  lon?: number;
+}
+
+export interface BriefingSlots {
+  compilation: boolean;
+  morning: boolean;
+  midday: boolean;
+  afternoon: boolean;
+}
+
+export interface BriefingConfig {
+  enabled: boolean;
+  locations: {
+    home?: BriefingLocation;
+    work?: BriefingLocation;
+  };
+  use_caldav_event_locations: boolean;
+  work_days: number[];
+  slots: BriefingSlots;
+  notifications: boolean;
+}
+
+export interface BriefingFeed {
+  id: number;
+  title: string;
+  url: string;
+  category: string | null;
+  last_fetched_at: string | null;
+}
+
+export interface BriefingConversation {
+  id: number;
+  title: string;
+  briefing_date: string | null;
+  message_count: number;
+  created_at: string;
+}
+
+export interface BriefingMessage {
+  id: number;
+  role: 'user' | 'assistant' | 'system';
+  content: string;
+  created_at: string;
+}
+
+const DEFAULT_BRIEFING_CONFIG: BriefingConfig = {
+  enabled: false,
+  locations: {},
+  use_caldav_event_locations: false,
+  work_days: [1, 2, 3, 4, 5],
+  slots: { compilation: true, morning: true, midday: false, afternoon: false },
+  notifications: true,
+};
+
+export async function getBriefingConfig(): Promise<BriefingConfig> {
+  try {
+    const data = await apiGet<BriefingConfig>('/api/briefing/config');
+    return { ...DEFAULT_BRIEFING_CONFIG, ...data };
+  } catch {
+    return { ...DEFAULT_BRIEFING_CONFIG };
+  }
+}
+
+export async function saveBriefingConfig(config: BriefingConfig): Promise<void> {
+  await apiPut('/api/briefing/config', config);
+}
+
+export async function getBriefingFeeds(): Promise<BriefingFeed[]> {
+  const data = await apiGet<BriefingFeed[]>('/api/briefing/feeds');
+  return data;
+}
+
+export async function createBriefingFeed(url: string): Promise<BriefingFeed> {
+  const data = await apiPost<{ id: number; url: string; title: string; category: string | null }>('/api/briefing/feeds', { url });
+  return { ...data, last_fetched_at: null };
+}
+
+export async function deleteBriefingFeed(id: number): Promise<void> {
+  await apiDelete(`/api/briefing/feeds/${id}`);
+}
+
+export async function getBriefingConversations(): Promise<BriefingConversation[]> {
+  const data = await apiGet<{ conversations: BriefingConversation[] }>('/api/briefing/conversations');
+  return data.conversations;
+}
+
+export async function getBriefingToday(): Promise<{ id: number; title: string; messages: BriefingMessage[] }> {
+  return apiGet('/api/briefing/conversations/today');
+}
+
+export async function getBriefingConvMessages(id: number): Promise<BriefingMessage[]> {
+  const data = await apiGet<{ messages: BriefingMessage[] }>(`/api/briefing/conversations/${id}/messages`);
+  return data.messages;
+}
+
+export async function triggerBriefingSlot(slot: string): Promise<void> {
+  await apiPost('/api/briefing/trigger', { slot });
+}
+
+export async function geocodeAddress(address: string): Promise<{ lat: number; lon: number; display_name: string } | null> {
+  try {
+    const r = await apiPost<{ lat: number; lon: number; label: string }>('/api/briefing/weather/geocode', { query: address });
+    return { lat: r.lat, lon: r.lon, display_name: r.label };
+  } catch {
+    return null;
+  }
+}
+
 export async function apiStreamPost(
   path: string,
   body: unknown,