Add OpenAPI docs, frontend, migrations, and API updates

- OpenAPI: add missing endpoints (add-from-url, subscriptions, public availability)
- OpenAPI: CalendarSubscription schema, Subscriptions tag
- Frontend app
- Migrations: count_for_availability, subscriptions_sync, user_preferences, calendar_settings
- Config, rate limit, auth, calendar, booking, ICS, availability, user service updates

Made-with: Cursor

internal/api/handlers/users.go

@@ -41,14 +41,34 @@ func (h *UserHandler) UpdateMe(w http.ResponseWriter, r *http.Request) {
 	}
 
 	var req struct {
-		Timezone *string `json:"timezone"`
+		Timezone                    *string `json:"timezone"`
+		WeekStartDay                *int    `json:"week_start_day"`
+		DateFormat                  *string `json:"date_format"`
+		TimeFormat                  *string `json:"time_format"`
+		DefaultEventDurationMinutes *int    `json:"default_event_duration_minutes"`
+		DefaultReminderMinutes      *int    `json:"default_reminder_minutes"`
+		ShowWeekends                *bool   `json:"show_weekends"`
+		WorkingHoursStart           *string `json:"working_hours_start"`
+		WorkingHoursEnd             *string `json:"working_hours_end"`
+		NotificationsEmail          *bool   `json:"notifications_email"`
 	}
 	if err := utils.DecodeJSON(r, &req); err != nil {
 		utils.WriteError(w, err)
 		return
 	}
 
-	user, err := h.userSvc.Update(r.Context(), userID, req.Timezone)
+	user, err := h.userSvc.Update(r.Context(), userID, &service.UserUpdateInput{
+		Timezone:                    req.Timezone,
+		WeekStartDay:                req.WeekStartDay,
+		DateFormat:                  req.DateFormat,
+		TimeFormat:                  req.TimeFormat,
+		DefaultEventDurationMinutes: req.DefaultEventDurationMinutes,
+		DefaultReminderMinutes:      req.DefaultReminderMinutes,
+		ShowWeekends:                req.ShowWeekends,
+		WorkingHoursStart:           req.WorkingHoursStart,
+		WorkingHoursEnd:             req.WorkingHoursEnd,
+		NotificationsEmail:          req.NotificationsEmail,
+	})
 	if err != nil {
 		utils.WriteError(w, err)
 		return