FIX(notifications): action_code accepts dots, PushMessage.stats actually updates

Found by an end-to-end run against a live Gotify container:

- action_code / NotificationLink.action_code were SlugField, which rejects
  dots. Every documented action_code (billboard.approved, escrow.timeout,
  ...) is dotted, so any real request using the catalog got a 400 before
  this fix -- only click_url ever worked. Switched both to CharField with
  a validator that keeps slug's charset but allows ".".
- send_push_notification set push_message.state instead of .stats after a
  successful send, so PushMessage.stats stayed stuck at INIT forever
  regardless of delivery outcome. Fixed the attribute name and scoped the
  save with update_fields.

Verified live: POST with a dotted action_code now resolves through
NotificationLink and lands in Gotify with the correct click.url, and the
PushMessage row flips to DONE.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/push_notifications/migrations/0007_alter_notificationlink_action_code_and_more.py

@@ -0,0 +1,24 @@
+# Generated by Django 5.2.6 on 2026-09-01 12:23
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('push_notifications', '0006_rename_code_notificationlink_action_code_and_more'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='notificationlink',
+            name='action_code',
+            field=models.CharField(db_index=True, max_length=100, unique=True, validators=[django.core.validators.RegexValidator(message='Enter a valid action code: letters, numbers, underscores, hyphens, or dots.', regex='^[-a-zA-Z0-9_.]+\\Z')]),
+        ),
+        migrations.AlterField(
+            model_name='pushmessage',
+            name='action_code',
+            field=models.CharField(blank=True, db_index=True, max_length=100, null=True, validators=[django.core.validators.RegexValidator(message='Enter a valid action code: letters, numbers, underscores, hyphens, or dots.', regex='^[-a-zA-Z0-9_.]+\\Z')]),
+        ),
+    ]

apps/push_notifications/models.py

@@ -1,3 +1,4 @@
+from django.core.validators import RegexValidator
 from django.db import models
 from oauth2_provider.settings import oauth2_settings
 
@@ -6,6 +7,15 @@ from utils.models import BaseModel
 from utils.clients import gotify
 from django.utils.translation import gettext_lazy as _
 
+# action_code values are dotted, e.g. "billboard.approved", "escrow.timeout"
+# (see docs/frontend-notification-click-actions.md) — a plain SlugField
+# rejects the dot, so every real call using the documented catalog gets a
+# 400 from the serializer. This mirrors slug's allowed charset but adds ".".
+validate_action_code = RegexValidator(
+    regex=r'^[-a-zA-Z0-9_.]+\Z',
+    message="Enter a valid action code: letters, numbers, underscores, hyphens, or dots.",
+)
+
 
 class PushUserQuerySet(models.QuerySet):
     def submit(self, user):
@@ -51,7 +61,7 @@ class NotificationLink(BaseModel):
     type) instead of a raw URL, so where a tap should navigate is a config
     change here, not a code deploy across every producer service.
     """
-    action_code = models.SlugField(max_length=100, unique=True, db_index=True)
+    action_code = models.CharField(max_length=100, unique=True, db_index=True, validators=[validate_action_code])
     description = models.CharField(max_length=255, blank=True)
     url_template = models.CharField(
         max_length=1000,
@@ -93,7 +103,7 @@ class PushMessage(BaseModel):
     # action_code, resolved against NotificationLink at send time (see
     # get_gotify_extras). click_object_id_value is substituted into that
     # action_code's {object_id} placeholder.
-    action_code = models.SlugField(max_length=100, null=True, blank=True, db_index=True)
+    action_code = models.CharField(max_length=100, null=True, blank=True, db_index=True, validators=[validate_action_code])
     click_object_id_value = models.CharField(max_length=255, null=True, blank=True)
     stats = models.IntegerField(default=StateChoices.INIT, choices=StateChoices.choices)
 

apps/push_notifications/tasks.py

@@ -11,8 +11,8 @@ def send_push_notification(push_message_uuid):
                       message=push_message.message,
                       priority=push_message.priority,
                       extras=push_message.get_gotify_extras())
-    push_message.state = push_message.StateChoices.DONE
-    push_message.save()
+    push_message.stats = push_message.StateChoices.DONE
+    push_message.save(update_fields=["stats"])
 
 
 @celery_app.task