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/calendar/PeriodPopover.test.tsx

@@ -388,17 +388,52 @@ describe('PeriodPopover', () => {
       })
     })
 
-    it('disables "this day" and shows why, for a wish-linked band (would just reappear on the next sync)', () => {
+    // Intent changed (was: '"this day" is disabled for a wish-linked band').
+    // A single day removed from a planner-placed period is now recorded as a
+    // `PlannedDayExclusion`, so it no longer reappears on the next sync and
+    // the option is live — see Calendar.tsx's `excludeDay`.
+    it('enables "this day" for a wish-linked band and explains what it does', () => {
       render(<PeriodPopover {...defaultProps} wish={wish} />)
-      expect(screen.getByTestId('period-delete-day-button')).toBeDisabled()
+      expect(screen.getByTestId('period-delete-day-button')).not.toBeDisabled()
       expect(screen.getByTestId('period-delete-day-button')).toHaveAttribute(
         'title',
-        "Går inte att ta bort en enskild dag från en återkommande plan — planeraren lägger tillbaka den vid nästa synk. Ta bort perioden istället.",
+        'Bara den dagen tas bort. Resten av perioden ligger kvar, och planeraren lägger inte tillbaka dagen.',
       )
       expect(screen.getByTestId('period-delete-year-button')).not.toBeDisabled()
       expect(screen.getByTestId('period-delete-all-years-button')).not.toBeDisabled()
     })
 
+    it('calls onDelete with the "day" scope for a wish-linked band after confirmation', async () => {
+      mockOnDelete.mockResolvedValue(undefined)
+      render(<PeriodPopover {...defaultProps} wish={wish} />)
+      fireEvent.click(screen.getByTestId('period-delete-day-button'))
+      fireEvent.click(screen.getByTestId('period-delete-confirm-button'))
+      await waitFor(() => expect(mockOnDelete).toHaveBeenCalledWith('day'))
+    })
+
+    it('names the date and the parent in the "this day" confirmation', () => {
+      render(
+        <PeriodPopover
+          {...defaultProps}
+          wish={wish}
+          removeDayLabel="17 juni 2028"
+          removeDayParentName="Alex"
+        />,
+      )
+      fireEvent.click(screen.getByTestId('period-delete-day-button'))
+      expect(screen.getByTestId('period-delete-confirm')).toHaveTextContent(
+        'Ta bort 17 juni 2028 för Alex?',
+      )
+    })
+
+    it('falls back to the generic confirmation when the parent is unknown', () => {
+      render(<PeriodPopover {...defaultProps} wish={wish} removeDayLabel="17 juni 2028" />)
+      fireEvent.click(screen.getByTestId('period-delete-day-button'))
+      expect(screen.getByTestId('period-delete-confirm')).toHaveTextContent(
+        'Är du säker på att du vill ta bort den här dagen?',
+      )
+    })
+
     it('displays a generic local error when onDelete rejects with a non-Error value', async () => {
       mockOnDelete.mockRejectedValue('boom')
       render(<PeriodPopover {...defaultProps} wish={wish} />)