Fix F&B last-7-days fill to span month boundary

"Fill F&B from last 7 days" only drew from the current month's elapsed
days, so early in a month (e.g. the 3rd) it only had 1-2 actual days to
repeat instead of a true trailing 7-day window. Add a dedicated
last7-fnb endpoint that fetches a real 7-day window ending yesterday,
reaching back into the prior month when needed.

backend/src/routes/directors-forecast.js

@@ -57,9 +57,38 @@ async function fetchMonthFromApi(year, month, lastDayNum, dowAlign = true) {
   return { revMap, roomsMap }
 }
 
+async function fetchLast7ActualsFnB() {
+  const today = new Date()
+  const end = new Date(today)
+  end.setDate(end.getDate() - 1)
+  const start = new Date(end)
+  start.setDate(start.getDate() - 6)
+  const startDate = start.toISOString().split('T')[0]
+
+  const revData = await fcFetch(`/forecast/revenue?start_date=${startDate}&days=7&type=all`)
+  return revData.data
+    .slice()
+    .sort((a, b) => a.date.localeCompare(b.date))
+    .map(d => ({
+      date: d.date,
+      actual_dry: d.dry?.otb ?? null,
+      actual_wet: d.wet?.otb ?? null,
+      forecast_dry: d.dry?.forecast ?? null,
+      forecast_wet: d.wet?.forecast ?? null,
+    }))
+}
+
 export async function directorsForecastRoutes(fastify) {
   fastify.addHook('preHandler', requireAuth)
 
+  // GET /api/directors-forecast/last7-fnb — trailing 7 actual F&B days ending
+  // yesterday, spanning a month boundary. Used by "fill F&B from last 7 days",
+  // which otherwise only has the current month's elapsed days to draw from.
+  fastify.get('/api/directors-forecast/last7-fnb', async (request, reply) => {
+    const days = await fetchLast7ActualsFnB()
+    return { days }
+  })
+
   // GET /api/directors-forecast/worksheet/:year/:month
   fastify.get('/api/directors-forecast/worksheet/:year/:month', async (request, reply) => {
     const year  = parseInt(request.params.year)