feat: add daily + global notes

tracker/models.py

@@ -122,6 +122,44 @@ class ReminderSent(models.Model):
         return f"{self.date} — {self.scheduled_dose}"
 
 
+class DailyNote(models.Model):
+    """Free-form journal entry for one day: appetite, behaviour, how Osiris is doing."""
+
+    date = models.DateField(default=timezone.localdate, unique=True)
+    body = models.TextField(blank=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        ordering = ["-date"]
+
+    def __str__(self):
+        return f"{self.date} — {self.body[:40]}"
+
+
+class GlobalNote(models.Model):
+    """The single shared note: standing instructions and things to do.
+
+    There is exactly one row, shared by everyone; the constraint pins its pk
+    so a second one cannot be created even by accident.
+    """
+
+    body = models.TextField(blank=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        constraints = [
+            models.CheckConstraint(condition=models.Q(id=1), name="single_global_note")
+        ]
+
+    def __str__(self):
+        return "Global note"
+
+    @classmethod
+    def load(cls) -> "GlobalNote":
+        note, _ = cls.objects.get_or_create(pk=1)
+        return note
+
+
 class PulseReading(models.Model):
     """One heart-rate measurement per day, in beats per minute."""