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/Enums.swift

@@ -198,14 +198,13 @@ extension GoalKind {
 
 /// How often a schedule expects its routine. Raw values are persisted in ScheduleDocument.
 enum ScheduleRecurrence: String, CaseIterable, Codable, Sendable {
-    case once, daily, fixedDays, frequency
+    case once, daily, fixedDays
 
     var displayName: String {
         switch self {
         case .once: "Once"
         case .daily: "Daily"
         case .fixedDays: "Fixed Days"
-        case .frequency: "Times per Week"
         }
     }
 }
@@ -213,10 +212,10 @@ enum ScheduleRecurrence: String, CaseIterable, Codable, Sendable {
 extension ScheduleRecurrence {
     /// Human-readable recurrence description shared by `ScheduleDocument` and the
     /// `Schedule` cache entity, so both render identically. `weekdays` uses Calendar
-    /// weekday numbers (1 = Sun … 7 = Sat); `timesPerWeek` is the frequency count;
-    /// `date` is the one-off day (`.once` only). A degenerate case (fixed days with no
-    /// weekdays, a nil count or date) falls back to the recurrence's own `displayName`.
-    func summary(weekdays: [Int]?, timesPerWeek: Int?, date: Date?) -> String {
+    /// weekday numbers (1 = Sun … 7 = Sat); `date` is the one-off day (`.once` only).
+    /// A degenerate case (fixed days with no weekdays, a nil date) falls back to the
+    /// recurrence's own `displayName`.
+    func summary(weekdays: [Int]?, date: Date?) -> String {
         switch self {
         case .once:
             return date?.formatDate() ?? displayName   // "Jul 12, 2026" / "Once"
@@ -230,8 +229,6 @@ extension ScheduleRecurrence {
                 (1...7).contains(n) ? symbols[n - 1] : nil
             }
             return names.isEmpty ? displayName : Self.joined(names)
-        case .frequency:
-            return "\(timesPerWeek ?? 0)× per week"
         }
     }