Show only the day's docket on the Today board and add ad hoc Now workouts

- Due-filter schedules: daily always, fixed days by weekday, one-offs on
  their date; rest days get an empty state
- Workouts with no due schedule row (ad hoc or off-day starts) now render
  as their own board rows
- The + sheet is now "New Workout" with a "When" picker; "Now" (offered
  when adding on today) skips the schedule and starts the workout directly
- Remove the times-per-week scheduling mode everywhere (enum, document,
  entity, mappers, planner, seeds, tests)

Shared/Model/Mappers.swift

@@ -91,7 +91,7 @@ extension ScheduleDocument {
         self.init(schemaVersion: Self.currentSchemaVersion, id: schedule.id,
                   routineID: schedule.routineID, routineName: schedule.routineName,
                   goal: schedule.goalRaw, recurrence: schedule.recurrenceRaw,
-                  weekdays: schedule.weekdays, timesPerWeek: schedule.timesPerWeek,
+                  weekdays: schedule.weekdays,
                   date: schedule.date,
                   order: schedule.order, createdAt: schedule.createdAt, updatedAt: schedule.updatedAt)
     }
@@ -255,7 +255,7 @@ enum CacheMapper {
         } else {
             schedule = Schedule(id: doc.id, routineID: doc.routineID, routineName: doc.routineName,
                                 goalRaw: doc.goal, recurrenceRaw: doc.recurrence, weekdays: doc.weekdays,
-                                timesPerWeek: doc.timesPerWeek, date: doc.date, order: doc.order,
+                                date: doc.date, order: doc.order,
                                 createdAt: doc.createdAt, updatedAt: doc.updatedAt,
                                 jsonRelativePath: relativePath)
             context.insert(schedule)
@@ -265,7 +265,6 @@ enum CacheMapper {
         schedule.goalRaw = doc.goal
         schedule.recurrenceRaw = doc.recurrence
         schedule.weekdays = doc.weekdays
-        schedule.timesPerWeek = doc.timesPerWeek
         schedule.date = doc.date
         schedule.order = doc.order
         schedule.createdAt = doc.createdAt