Widen actuals fetch window so the hop-back forecast fallback can reach history

Monthly.tsx and Dashboard.tsx only ever fetched actuals for the current
period (month-start..month-end, or a 7-day lookback for the week view),
but forecastDayCost's same-weekday fallback hops back up to 42 days
looking for a match. For any early-period date whose hop landed before
the fetch window started, that data was never in memory at all — it
silently fell through to the 'none' tier (£0) once published rota ran
out, rather than finding a real historical match.

ai-insights.js's gatherForecastData already fetched a proper 42-day
lookback; these two pages didn't. Widened both fetches to match, with
explicit >= period-start filters on the actual-sum calculations so the
extra history is only ever used by the hop fallback, never counted
twice into "actual".

frontend/src/pages/Dashboard.tsx

@@ -92,7 +92,6 @@ export default function Dashboard() {
 
       const weekFrom      = mondayOf(new Date())
       const weekTo        = addDaysStr(weekFrom, 6)
-      const prevWeekFrom  = addDaysStr(weekFrom, -7)
       const weekMonthKeys = Array.from(new Set([monthKeyOf(weekFrom), monthKeyOf(weekTo)]))
       const weekDates     = Array.from({ length: 7 }, (_, i) => addDaysStr(weekFrom, i))
       const weekElapsed   = weekDates.filter(d => d <= yesterdayStr).length
@@ -104,11 +103,19 @@ export default function Dashboard() {
       const monthDates = Array.from({ length: dim }, (_, i) => `${monthKey}-${String(i + 1).padStart(2, '0')}`)
       const monthElapsed = monthDates.filter(d => d <= yesterdayStr).length
 
+      // forecastDayCost hops back up to 42 days looking for a same-weekday actual — fetch
+      // that much extra history before each period start so early-period dates can actually
+      // find it, instead of falling through to the 'none' tier once rota runs out. The actual
+      // sums below stay explicitly bounded to weekFrom/monthFrom, so this extra history is
+      // only ever used for the hop fallback, never double-counted into "actual".
+      const weekActualsFrom  = addDaysStr(weekFrom, -42)
+      const monthActualsFrom = addDaysStr(monthFrom, -42)
+
       const [weekActRes, weekSchedRes, weekSalesRes, monthActRes, monthSchedRes, monthSalesRes, budgetRes] = await Promise.all([
-        getActuals(prevWeekFrom, weekTo),
+        getActuals(weekActualsFrom, weekTo),
         getScheduled(weekFrom, weekTo),
         getNetSales(weekFrom, weekTo),
-        getActuals(monthFrom, monthTo),
+        getActuals(monthActualsFrom, monthTo),
         getScheduled(monthFrom, monthTo),
         getNetSales(monthFrom, monthTo),
         getBudgets(),
@@ -149,7 +156,7 @@ export default function Dashboard() {
       // ── Month ─────────────────────────────────────────────────────
       const monthDeptRows = monthActRes.departments.map(dep => {
         const actual = Object.entries(dep.days)
-          .filter(([d]) => d <= yesterdayStr)
+          .filter(([d]) => d >= monthFrom && d <= yesterdayStr)
           .reduce((s, [, v]) => s + v.cost, 0)
         let forecast = actual
         const schedDep = monthActRes.forecast_method === 'rota'

frontend/src/pages/Monthly.tsx

@@ -63,6 +63,12 @@ export default function Monthly() {
   const toStr          = `${monthStr}-${String(dim).padStart(2, '0')}`
   const isCurrentMonth = year === todayYear && month === todayMonth
 
+  // forecastDayCost hops back up to 42 days looking for a same-weekday actual — fetch that
+  // much extra history before the month start so early-month dates can actually find it,
+  // instead of falling through to the 'none' tier once rota runs out. actualMTD/etc. below
+  // still filter to >= fromStr, so this extra history is only ever used for the hop fallback.
+  const actualsFromStr = fmt(addDays(new Date(fromStr + 'T00:00:00'), -42))
+
   // Prior year: always fetch full month (derive both MTD and full totals from one call)
   const pyDim     = daysInMonth(year - 1, month)
   const pyFromStr = `${year - 1}-${String(month).padStart(2, '0')}-01`
@@ -80,7 +86,7 @@ export default function Monthly() {
     try {
       // Net sales: full month — OTB/forecast for future dates, actuals for past dates
       const [actRes, schedRes, salesRes, budRes, pyActRes, pmActRes] = await Promise.all([
-        getActuals(fromStr, toStr),
+        getActuals(actualsFromStr, toStr),
         getScheduled(fromStr, toStr),
         getNetSales(fromStr, toStr),
         getBudgets(),
@@ -136,7 +142,7 @@ export default function Monthly() {
     } finally {
       setLoading(false)
     }
-  }, [fromStr, toStr, pyFromStr, pyToStr, pmFromStr, pmToStr, isCurrentMonth, yesterdayStr, year, month, pyDim])
+  }, [fromStr, toStr, actualsFromStr, pyFromStr, pyToStr, pmFromStr, pmToStr, isCurrentMonth, yesterdayStr, year, month, pyDim])
 
   useEffect(() => { load() }, [load])