feat: show transport bookings in day plan timeline — closes #37

Transport reservations (flights, trains, buses, cars, cruises) now appear
directly in the day plan timeline based on their reservation date/time.

- Transport cards display inline with places and notes, sorted by time
- Click to open detail modal with all booking data and linked files
- Persistent positioning via new day_plan_position field on reservations
- Free drag & drop: places can be moved between/around transport entries
- Arrow reorder works on the full visual list including transports
- Timed places show confirmation popup when reorder breaks chronology
- Custom delete confirmation popup for reservations
- DB migration adds day_plan_position column to reservations table
- New batch endpoint PUT /reservations/positions for position updates
- i18n keys added for DE and EN

server/src/db/migrations.ts

@@ -321,6 +321,10 @@ function runMigrations(db: Database.Database): void {
         UNIQUE(file_id, place_id)
       )`);
     },
+    () => {
+      // Add day_plan_position to reservations for persistent transport ordering in day timeline
+      try { db.exec('ALTER TABLE reservations ADD COLUMN day_plan_position REAL DEFAULT NULL'); } catch {}
+    },
   ];
 
   if (currentVersion < migrations.length) {

server/src/routes/reservations.ts

@@ -103,6 +103,29 @@ router.post('/', authenticate, (req: Request, res: Response) => {
   broadcast(tripId, 'reservation:created', { reservation }, req.headers['x-socket-id'] as string);
 });
 
+// Batch update day_plan_position for multiple reservations (must be before /:id)
+router.put('/positions', authenticate, (req: Request, res: Response) => {
+  const authReq = req as AuthRequest;
+  const { tripId } = req.params;
+  const { positions } = req.body;
+
+  const trip = verifyTripOwnership(tripId, authReq.user.id);
+  if (!trip) return res.status(404).json({ error: 'Trip not found' });
+
+  if (!Array.isArray(positions)) return res.status(400).json({ error: 'positions must be an array' });
+
+  const stmt = db.prepare('UPDATE reservations SET day_plan_position = ? WHERE id = ? AND trip_id = ?');
+  const updateMany = db.transaction((items: { id: number; day_plan_position: number }[]) => {
+    for (const item of items) {
+      stmt.run(item.day_plan_position, item.id, tripId);
+    }
+  });
+  updateMany(positions);
+
+  res.json({ success: true });
+  broadcast(tripId, 'reservation:positions', { positions }, req.headers['x-socket-id'] as string);
+});
+
 router.put('/:id', authenticate, (req: Request, res: Response) => {
   const authReq = req as AuthRequest;
   const { tripId, id } = req.params;