fix(vacay): allow vacation on public holidays and add today marker

Removes the client-side guard that blocked toggling vacation entries on
public holiday dates, so users who work on holidays can still book leave.
Also adds a filled blue circle on today's date in the Vacay calendar for
quick orientation.

Closes #651

client/src/components/Vacay/VacayCalendar.test.tsx

@@ -151,7 +151,7 @@ describe('VacayCalendar', () => {
     expect(toggleEntry).toHaveBeenCalledWith('2025-01-01', 42)
   })
 
-  it('FE-COMP-VACAYCALENDAR-007: cell click blocked by public holiday', async () => {
+  it('FE-COMP-VACAYCALENDAR-007: cell click on public holiday toggles vacation entry', async () => {
     const user = userEvent.setup()
     const toggleEntry = vi.fn().mockResolvedValue(undefined)
 
@@ -168,10 +168,10 @@ describe('VacayCalendar', () => {
 
     render(<VacayCalendar />)
 
-    // Month 0, button emits '2025-01-01' which is a holiday
+    // Month 0, button emits '2025-01-01' which is a holiday — should still toggle vacation
     await user.click(screen.getByText('click-0'))
 
-    expect(toggleEntry).not.toHaveBeenCalled()
+    expect(toggleEntry).toHaveBeenCalledWith('2025-01-01', undefined)
   })
 
   it('FE-COMP-VACAYCALENDAR-008: cell click in company mode calls toggleCompanyHoliday', async () => {

client/src/components/Vacay/VacayCalendar.tsx

@@ -60,11 +60,10 @@ export default function VacayCalendar() {
       await toggleCompanyHoliday(dateStr)
       return
     }
-    if (holidays[dateStr]) return
     if (blockWeekends && isWeekend(dateStr, weekendDays)) return
     if (companyHolidaysEnabled && companyHolidaySet.has(dateStr)) return
     await toggleEntry(dateStr, selectedUserId || undefined)
-  }, [companyMode, toggleEntry, toggleCompanyHoliday, holidays, companyHolidaySet, blockWeekends, companyHolidaysEnabled, selectedUserId])
+  }, [companyMode, toggleEntry, toggleCompanyHoliday, companyHolidaySet, blockWeekends, companyHolidaysEnabled, selectedUserId])
 
   const selectedUser = users.find(u => u.id === selectedUserId)
 

client/src/components/Vacay/VacayMonthCard.tsx

@@ -54,6 +54,11 @@ export default function VacayMonthCard({
 
   const pad = (n) => String(n).padStart(2, '0')
 
+  const todayStr = useMemo(() => {
+    const d = new Date()
+    return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`
+  }, [])
+
   return (
     <div className="rounded-xl border overflow-hidden" style={{ background: 'var(--bg-card)', borderColor: 'var(--border-primary)' }}>
       <div className="px-3 py-2 border-b" style={{ borderColor: 'var(--border-secondary)' }}>
@@ -85,7 +90,8 @@ export default function VacayMonthCard({
               const holiday = holidays[dateStr]
               const isCompany = companyHolidaysEnabled && companyHolidaySet.has(dateStr)
               const dayEntries = entryMap[dateStr] || []
-              const isBlocked = !!holiday || (weekend && blockWeekends) || (isCompany && !companyMode)
+              const isBlocked = (weekend && blockWeekends) || (isCompany && !companyMode)
+              const isToday = dateStr === todayStr
 
               return (
                 <div
@@ -135,9 +141,24 @@ export default function VacayMonthCard({
                     <span className="absolute top-[3px] right-[3px] w-[5px] h-[5px] rounded-full z-[2]" style={{ background: '#3b82f6' }} />
                   )}
 
-                  <span className="relative z-[1] text-[11px] font-medium" style={{
+                  <span className="relative z-[1] text-[11px]" style={{
-                    color: holiday ? holiday.color : weekend ? 'var(--text-faint)' : 'var(--text-primary)',
                     fontWeight: dayEntries.length > 0 ? 700 : 500,
+                    color: isToday
+                      ? '#fff'
+                      : dayEntries.length > 0
+                        ? 'var(--text-primary)'
+                        : holiday ? holiday.color
+                        : weekend ? 'var(--text-faint)'
+                        : 'var(--text-primary)',
+                    ...(isToday ? {
+                      display: 'inline-flex',
+                      alignItems: 'center',
+                      justifyContent: 'center',
+                      width: 18,
+                      height: 18,
+                      borderRadius: '50%',
+                      background: '#3b82f6',
+                    } : {}),
                   }}>
                     {day}
                   </span>