Reorder whole days and insert a day (#589) (#1148)

* feat(days): reorder whole days and insert a day at a position

Adds reorderDays + insertDay to the day service and a PUT /days/reorder route
(plus an optional position on create). Day rows stay stable so a day's
assignments, notes, bookings and accommodations ride along by id; on a dated
trip the calendar dates stay pinned to their slots while the content moves
across them, and each booking's date is re-stamped onto its day's new date
(time-of-day preserved) so day_id stays consistent. Renumbering uses the
two-phase write to avoid the UNIQUE(trip_id, day_number) collision, and a move
that would invert an accommodation's check-in/out span is rejected.

* feat(planner): reorder days from a toolbar popup, and add days

A new toolbar button opens a popup listing the days; drag a row by its grip or
use the up/down arrows to reorder, and add a day from there. Reorders apply
optimistically with rollback and sync over WebSocket; the day headers are left
untouched, so the existing place drop-targets are unaffected.

* i18n: add day-reorder strings across all languages

client/src/components/Planner/DayPlanSidebar.tsx

@@ -51,6 +51,8 @@ interface DayPlanSidebarProps {
   onDayDetail: (day: Day) => void
   accommodations?: Accommodation[]
   onReorder: (dayId: number, orderedIds: number[]) => void
+  onReorderDays?: (orderedIds: number[]) => void
+  onAddDay?: (position?: number) => void
   onUpdateDayTitle: (dayId: number, title: string) => void
   onRouteCalculated: (route: RouteResult | null) => void
   onAssignToDay: (placeId: number, dayId: number, position?: number) => void
@@ -96,7 +98,7 @@ function useDayPlanSidebar(props: DayPlanSidebarProps) {
   trip, days, places, categories, assignments,
   selectedDayId, selectedPlaceId, selectedAssignmentId,
   onSelectDay, onPlaceClick, onDayDetail, accommodations = [],
-  onReorder, onUpdateDayTitle, onRouteCalculated,
+  onReorder, onReorderDays, onAddDay, onUpdateDayTitle, onRouteCalculated,
   onAssignToDay, onRemoveAssignment, onEditPlace, onDeletePlace,
   reservations = [],
   visibleConnectionIds = [],
@@ -866,6 +868,8 @@ function useDayPlanSidebar(props: DayPlanSidebarProps) {
     onDayDetail,
     accommodations,
     onReorder,
+    onReorderDays,
+    onAddDay,
     onUpdateDayTitle,
     onRouteCalculated,
     onAssignToDay,
@@ -1010,6 +1014,8 @@ const DayPlanSidebar = React.memo(function DayPlanSidebar(props: DayPlanSidebarP
     onDayDetail,
     accommodations,
     onReorder,
+    onReorderDays,
+    onAddDay,
     onUpdateDayTitle,
     onRouteCalculated,
     onAssignToDay,
@@ -1161,6 +1167,9 @@ const DayPlanSidebar = React.memo(function DayPlanSidebar(props: DayPlanSidebarP
         undoHover={undoHover}
         setUndoHover={setUndoHover}
         lastActionLabel={lastActionLabel}
+        canEditDays={canEditDays}
+        onReorderDays={onReorderDays}
+        onAddDay={onAddDay}
       />
 
       {/* Tagesliste */}