feat(mobile): make the bottom-nav "+" context-aware per trip tab (#1349)

On mobile the bottom-nav "+" always created a new place (except on the Costs tab,
where it added an expense). It now matches the active trip tab: Bookings adds a
reservation, Transports adds a transport, Costs adds an expense, and everything
else (Plan, plus tabs that have no create modal — Lists / Files / Collab) keeps
adding a place.

Follows the existing ?create=<intent> pattern: BottomNav.useCreateAction emits the
per-tab intent, and useTripPlanner consumes create=reservation|transport to open
the booking / transport modals (both already mounted at page level). Place and
expense were already wired; this just extends the mapping.

Tests: 4 new BottomNav cases (plan/bookings/transports/costs → correct intent +
navigate target); client tsc clean, full client suite green (2855).

Implements mauriceboe/TREK#1349

client/src/components/Layout/BottomNav.test.tsx

@@ -1,4 +1,4 @@
-// FE-COMP-BOTTOMNAV-001 to FE-COMP-BOTTOMNAV-006
+// FE-COMP-BOTTOMNAV-001 to FE-COMP-BOTTOMNAV-010
 
 vi.mock('../../api/websocket', () => ({
   connect: vi.fn(),
@@ -30,6 +30,7 @@ const currentUser = buildUser({ id: 1, username: 'testuser', email: 'test@exampl
 beforeEach(() => {
   resetAllStores();
   mockNavigate.mockClear();
+  sessionStorage.clear();
   seedStore(useAuthStore, { user: currentUser, isAuthenticated: true });
 });
 
@@ -79,4 +80,37 @@ describe('BottomNav', () => {
     render(<BottomNav />);
     expect(screen.queryByText('Foo Addon')).not.toBeInTheDocument();
   });
+
+  // Context-aware "+" inside a trip — #1349
+  it('FE-COMP-BOTTOMNAV-007: in a trip, the "+" adds a place by default (plan tab)', async () => {
+    const user = userEvent.setup();
+    sessionStorage.setItem('trip-tab-42', 'plan');
+    render(<BottomNav />, { initialEntries: ['/trips/42'] });
+    await user.click(screen.getByRole('button', { name: 'Add Place/Activity' }));
+    expect(mockNavigate).toHaveBeenCalledWith('/trips/42?create=place');
+  });
+
+  it('FE-COMP-BOTTOMNAV-008: Bookings tab → "+" creates a reservation', async () => {
+    const user = userEvent.setup();
+    sessionStorage.setItem('trip-tab-42', 'buchungen');
+    render(<BottomNav />, { initialEntries: ['/trips/42'] });
+    await user.click(screen.getByRole('button', { name: 'Manual Booking' }));
+    expect(mockNavigate).toHaveBeenCalledWith('/trips/42?create=reservation');
+  });
+
+  it('FE-COMP-BOTTOMNAV-009: Transports tab → "+" creates a transport', async () => {
+    const user = userEvent.setup();
+    sessionStorage.setItem('trip-tab-42', 'transports');
+    render(<BottomNav />, { initialEntries: ['/trips/42'] });
+    await user.click(screen.getByRole('button', { name: 'Manual Transport' }));
+    expect(mockNavigate).toHaveBeenCalledWith('/trips/42?create=transport');
+  });
+
+  it('FE-COMP-BOTTOMNAV-010: Costs tab → "+" creates an expense', async () => {
+    const user = userEvent.setup();
+    sessionStorage.setItem('trip-tab-42', 'finanzplan');
+    render(<BottomNav />, { initialEntries: ['/trips/42'] });
+    await user.click(screen.getByRole('button', { name: 'Add expense' }));
+    expect(mockNavigate).toHaveBeenCalledWith('/trips/42?create=expense');
+  });
 });

client/src/components/Layout/BottomNav.tsx

@@ -25,12 +25,15 @@ function useCreateAction(): { label: string; run: () => void } {
   const onJourneyList = useMatch('/journey')
 
   if (inTrip) {
-    // On the Costs tab the "+" adds an expense; otherwise it adds a place.
-    const tripTab = typeof sessionStorage !== 'undefined' ? sessionStorage.getItem(`trip-tab-${inTrip.params.id}`) : null
-    if (tripTab === 'finanzplan') {
-      return { label: t('costs.addExpense'), run: () => navigate(`/trips/${inTrip.params.id}?create=expense`) }
-    }
-    return { label: t('places.addPlace'), run: () => navigate(`/trips/${inTrip.params.id}?create=place`) }
+    // The "+" is context-aware per active tab: Bookings → reservation,
+    // Transports → transport, Costs → expense. Tabs without a create modal
+    // (lists / files / collab) fall through to adding a place. #1349
+    const id = inTrip.params.id
+    const tripTab = typeof sessionStorage !== 'undefined' ? sessionStorage.getItem(`trip-tab-${id}`) : null
+    if (tripTab === 'finanzplan') return { label: t('costs.addExpense'), run: () => navigate(`/trips/${id}?create=expense`) }
+    if (tripTab === 'buchungen') return { label: t('reservations.addManual'), run: () => navigate(`/trips/${id}?create=reservation`) }
+    if (tripTab === 'transports') return { label: t('transport.addManual'), run: () => navigate(`/trips/${id}?create=transport`) }
+    return { label: t('places.addPlace'), run: () => navigate(`/trips/${id}?create=place`) }
   }
   if (inJourney) {
     return { label: t('journey.detail.addEntry'), run: () => navigate(`/journey/${inJourney.params.id}?create=entry`) }

client/src/pages/tripPlanner/useTripPlanner.ts

@@ -161,6 +161,20 @@ export function useTripPlanner() {
   const [showTransportModal, setShowTransportModal] = useState<boolean>(false)
   const [editingTransport, setEditingTransport] = useState<Reservation | null>(null)
   const [transportModalDayId, setTransportModalDayId] = useState<number | null>(null)
+
+  // The bottom-nav "+" is context-aware per tab: on the Bookings / Transports tabs
+  // it opens the booking / transport modal via ?create=reservation|transport
+  // (place is handled above, expense in CostsPanel). #1349
+  useEffect(() => {
+    const intent = searchParams.get('create')
+    if (intent === 'reservation') {
+      setEditingReservation(null); setBookingForAssignmentId(null); setShowReservationModal(true)
+      setSearchParams(p => { p.delete('create'); return p }, { replace: true })
+    } else if (intent === 'transport') {
+      setEditingTransport(null); setTransportModalDayId(null); setShowTransportModal(true)
+      setSearchParams(p => { p.delete('create'); return p }, { replace: true })
+    }
+  }, [searchParams])
   // Review-before-save import: each parsed item pre-fills the normal edit modal so
   // the user checks/fixes it, then saves. A ref drives the queue (no stale closures).
   const [reservationPrefill, setReservationPrefill] = useState<BookingReviewDraft | null>(null)