Let a day removed from a period stay removed

Taking one day out of a period the planner placed did nothing that
lasted: the period still asked for a full week, so the next sync put the
day straight back. The option was disabled rather than lying about it.

A removed day is now recorded as its own thing — no leave for this
parent, this child, this date — and the planner honours it on every
later sync. It is kept apart from the working-day overrides, which
answer a different question about the calendar rather than about the
plan.

The day belongs to the parent whose band was clicked, so removing one
parent's day leaves their partner's alone; where both parents were to be
off on one funding arrangement, the partner is simply funded on their
own instead. A removed day shortens what the period is asking for rather
than counting as a day the plan failed to find, so the advice about
closing a shortfall does not start arguing for a day nobody wants.

Nothing is removed without a way back: the toast undoes it, and the day
itself is marked in the calendar and offers to restore.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ei7gCZzdd751uZtPzb1Pep

frontend/src/components/common/CalendarWeek.tsx

@@ -14,6 +14,11 @@ export interface BandClickInfo {
   parentPersonalDataUuid: string
   startDate: string
   endDate: string
+  /** The single date the user actually clicked inside the band, which is what
+   * the popover's "this day" removes. Clicking the band anywhere else (or
+   * activating it from the keyboard) reports the band's own start date, so
+   * this is never empty. */
+  clickedDate: string
 }
 
 export interface CalendarWeekProps {
@@ -42,6 +47,11 @@ export interface CalendarWeekProps {
   onPointerEnter: (date: string) => void
   /** §3.4/§3.6 — calendar metadata (röda dagar/klämdagar/overrides) keyed by ISO date. */
   calendarDaysByDate?: Map<string, CalendarDayEntry> | undefined
+  /** Dates the user has removed from the plan by hand (see
+   * `PlannedDayExclusion`). A date the planner deliberately skipped inside an
+   * otherwise-funded period is invisible otherwise, and the hole in the week
+   * looks like a bug. */
+  excludedDates?: Set<string> | undefined
   /** Opens the period editor for the clicked band's underlying period. */
   onBandClick?: ((info: BandClickInfo) => void) | undefined
   /** §Task7 — the wishId of a just-created/just-edited period to briefly
@@ -283,6 +293,7 @@ export function CalendarWeek({
   onPointerDown,
   onPointerEnter,
   calendarDaysByDate,
+  excludedDates,
   onBandClick,
   flashWishId,
   monthMaxLaneCount,
@@ -352,6 +363,7 @@ export function CalendarWeek({
               holidayName={calendarInfo?.name ?? null}
               isOverride={calendarInfo?.isOverride ?? false}
               overrideIsWorkingDay={calendarInfo?.overrideIsWorkingDay ?? null}
+              isExcluded={excludedDates?.has(date) ?? false}
               // Every cell is clickable/drag-selectable regardless of which
               // month it visually belongs to — `dayIsCurrentMonth` only
               // controls the dimmed `calendar-day--disabled` styling above.
@@ -394,12 +406,15 @@ export function CalendarWeek({
           .filter(Boolean)
           .join(' ')
 
-        const fireClick = () =>
+        const fireClick = (clickedDate?: string) =>
           onBandClick?.({
             wishId: segment.wishId,
             parentPersonalDataUuid: segment.parentUuid,
             startDate: segment.overallStart,
             endDate: segment.overallEnd,
+            // Falls back to the band's first date when the click didn't land
+            // on a specific day slot (the band's padding, or the keyboard).
+            clickedDate: clickedDate ?? segment.overallStart,
           })
 
         return (
@@ -417,7 +432,7 @@ export function CalendarWeek({
             aria-label={`${label} · ${typeLabel}, ${segment.overallStart} – ${segment.overallEnd}`}
             role={onBandClick ? 'button' : undefined}
             tabIndex={onBandClick ? 0 : undefined}
-            onClick={onBandClick ? fireClick : undefined}
+            onClick={onBandClick ? () => fireClick() : undefined}
             onKeyDown={
               onBandClick
                 ? (e) => {
@@ -443,6 +458,18 @@ export function CalendarWeek({
                   style={info.isGap ? undefined : { backgroundColor: getColorForType(info.dayType ?? 'vacation') }}
                   title={info.isPinned ? t('calendarDay.pinnedAria') : undefined}
                   data-testid={info.isPinned ? 'calendar-band-day-pinned' : undefined}
+                  // Clicking one day slot opens the same popover as clicking
+                  // the band, but tells it WHICH date was clicked — "this
+                  // day" must be able to remove a day in the middle of a
+                  // period, not only its first.
+                  onClick={
+                    onBandClick
+                      ? (e) => {
+                          e.stopPropagation()
+                          fireClick(info.date)
+                        }
+                      : undefined
+                  }
                 />
               ))}
             </div>