Finish converting CLI commands to use peewee

hamstertools/db.py

@@ -1,5 +1,5 @@
 import logging
-from peewee import SqliteDatabase, Model, CharField, ForeignKeyField
+from peewee import SqliteDatabase, Model, CharField, ForeignKeyField, DateTimeField
 
 from textual.logging import TextualHandler
 
@@ -29,6 +29,9 @@ class HamsterActivity(Model):
 
 class HamsterFact(Model):
     activity = ForeignKeyField(HamsterActivity, backref='facts')
+    start_time = DateTimeField()
+    end_time = DateTimeField(null=True)
+    description = CharField()
 
     class Meta:
         database = db