ui+server: schedule next-run / last-run on dashboard + schedules tab

P2R-14. New store.LatestJobBySchedule query (per-schedule fired job).
Schedules-tab handler computes next-fire from cron + last-fire from
the jobs table per row. Schedules table grows two columns; dashboard
host row prepends 'next 12h ago/from now' to the existing last-backup
line when a single covering schedule is the run-now candidate.

Embeds store.Schedule into scheduleRow so existing template field
references keep working without bulk renames.

internal/server/http/ui_schedules.go

@@ -25,10 +25,22 @@ import (
 // the template doesn't need to do per-row store lookups.
 type hostSchedulesPage struct {
 	hostChromeData
-	Schedules  []store.Schedule
+	Schedules  []scheduleRow
 	GroupNames map[string]string
 }
 
+// scheduleRow bundles a schedule with its derived "next run" + "last
+// run" data. The Schedule is embedded so existing template field
+// references (`$sc.ID`, `$sc.CronExpr`, etc) keep working when we
+// switch the iterating slice from []store.Schedule to []scheduleRow.
+type scheduleRow struct {
+	store.Schedule
+	NextRun    *time.Time
+	LastRun    *time.Time
+	LastJobID  string
+	LastStatus string // succeeded|failed|running|queued — empty when never fired
+}
+
 // scheduleFormData mirrors the form's wire shape — strings + bool for
 // round-trip on validation re-render.
 type scheduleFormData struct {
@@ -74,6 +86,28 @@ func (s *Server) handleUISchedulesList(w stdhttp.ResponseWriter, r *stdhttp.Requ
 		names[g.ID] = g.Name
 	}
 
+	now := time.Now().UTC()
+	rows := make([]scheduleRow, 0, len(scheds))
+	for _, sc := range scheds {
+		row := scheduleRow{Schedule: sc}
+		if sc.Enabled {
+			if sched, err := cronParser.Parse(sc.CronExpr); err == nil {
+				next := sched.Next(now).UTC()
+				row.NextRun = &next
+			}
+		}
+		if j, jerr := s.deps.Store.LatestJobBySchedule(r.Context(), host.ID, sc.ID); jerr == nil && j != nil {
+			t := j.CreatedAt
+			if j.StartedAt != nil {
+				t = *j.StartedAt
+			}
+			row.LastRun = &t
+			row.LastJobID = j.ID
+			row.LastStatus = j.Status
+		}
+		rows = append(rows, row)
+	}
+
 	chrome := s.loadHostChrome(r, *host, "schedules", "schedules")
 	chrome.ScheduleCount = len(scheds)
 	chrome.SourceGroupCount = len(groups)
@@ -82,7 +116,7 @@ func (s *Server) handleUISchedulesList(w stdhttp.ResponseWriter, r *stdhttp.Requ
 	view.Title = host.Name + " schedules · restic-manager"
 	view.Page = hostSchedulesPage{
 		hostChromeData: chrome,
-		Schedules:      scheds,
+		Schedules:      rows,
 		GroupNames:     names,
 	}
 	if err := s.deps.UI.Render(w, "host_schedules", view); err != nil {