fix (schedule): Setting tweaks and more bugfixes.

Add the schedule dashboard to the config dashboard.
Move the schedule cost to the second page.
Allow categories to be selected for the session room.

Fix an issue where blacklist role would be checked with no guild data.
Fix typos in session unloading.
Delay session notification.
More logging.

src/modules/schedule/cog.py

@@ -87,7 +87,7 @@ class ScheduleCog(LionCog):
                 slot.run_task.cancel()
             for session in slot.sessions.values():
                 if session._updater and not session._updater.done():
-                    session._update.cancel()
+                    session._updater.cancel()
                 if session._status_task and not session._status_task.done():
                     session._status_task.cancel()
 
@@ -217,21 +217,23 @@ class ScheduleCog(LionCog):
             for bookingid in bookingids:
                 await self._cancel_booking_active(*bookingid)
 
-            # Now delete from data
-            records = await self.data.ScheduleSessionMember.table.delete_where(
-                MULTIVALUE_IN(
-                    ('slotid', 'guildid', 'userid'),
-                    *bookingids
+            conn = await self.bot.db.get_connection()
+            async with conn.transaction():
+                # Now delete from data
+                records = await self.data.ScheduleSessionMember.table.delete_where(
+                    MULTIVALUE_IN(
+                        ('slotid', 'guildid', 'userid'),
+                        *bookingids
+                    )
                 )
-            )
 
-            # Refund cancelled bookings
-            if refund:
-                maybe_tids = (record['book_transactionid'] for record in records)
-                tids = [tid for tid in maybe_tids if tid is not None]
-                if tids:
-                    economy = self.bot.get_cog('Economy')
-                    await economy.data.Transaction.refund_transactions(*tids)
+                # Refund cancelled bookings
+                if refund:
+                    maybe_tids = (record['book_transactionid'] for record in records)
+                    tids = [tid for tid in maybe_tids if tid is not None]
+                    if tids:
+                        economy = self.bot.get_cog('Economy')
+                        await economy.data.Transaction.refund_transactions(*tids)
         finally:
             for lock in locks:
                 lock.release()
@@ -240,6 +242,7 @@ class ScheduleCog(LionCog):
         )
         return records
 
+    @log_wrap(action='Cancel Active Booking')
     async def _cancel_booking_active(self, slotid, guildid, userid):
         """
         Booking cancel worker for active slots.
@@ -259,7 +262,7 @@ class ScheduleCog(LionCog):
                 return
             async with session.lock:
                 # Update message if it has already been sent
-                session.update_message_soon(resend=False)
+                session.update_status_soon(resend=False)
                 room = session.room_channel
                 member = session.guild.get_member(userid) if room else None
                 if room and member and session.prepared:
@@ -564,7 +567,7 @@ class ScheduleCog(LionCog):
         if new_roles:
             # This should be in cache in the vast majority of cases
             guild_data = await self.data.ScheduleGuild.fetch(guild.id)
-            if (roleid := guild_data.blacklist_role) is not None and roleid in new_roles:
+            if guild_data and (roleid := guild_data.blacklist_role) is not None and roleid in new_roles:
                 # Clear member schedule
                 await self.clear_member_schedule(guild.id, after.id)