docs: Document Error Tracking weekly digest per-project settings

contents/docs/error-tracking/alerts.mdx

@@ -68,6 +68,13 @@ Here you can set alerts for event volume value, increase, or decrease.
 
 This sends an email notification to the user you choose. Check out our [alerts docs](/docs/alerts) for more information.
 
+### Weekly digest emails
+
+PostHog sends a weekly Error Tracking digest email every Monday with a summary of exceptions across your projects. You receive one email per organization, with a section for each enabled project showing exception counts, top issues, and week-over-week trends.
+
+You can configure which projects to include in the digest under [**Account > Notifications**](https://app.posthog.com/settings/user-notifications). If you haven't selected any projects, PostHog automatically picks the one with the most exceptions on the first digest run. You can override this by selecting projects manually.
+
+
 import { CalloutBox } from 'components/Docs/CalloutBox'
 
 <CalloutBox icon="IconInfo" title="Can't find your alert?" type="fyi">

contents/docs/settings/account-settings.mdx

@@ -38,7 +38,24 @@ To enable 2FA, go to [your account settings](https://us.posthog.com/settings/use
 
 ## Notifications
 
-You can choose which email notifications you receive in [your account settings](https://us.posthog.com/settings/user#notifications) under **Notifications**. You can enable or disable specific notifications with toggles. Product-specific notification, such as [Alerts](/docs/alerts), have separate configurations in each product.
+You can choose which email notifications you receive in [your account settings](https://us.posthog.com/settings/user#notifications) under **Notifications**. You can enable or disable specific notifications with toggles. Product-specific notifications, such as [Alerts](/docs/alerts), have separate configurations in each product.
+
+Available notifications include:
+
+- **Security alerts** - Password changes, 2FA, login activity, and API key exposure. Always enabled.
+- **Weekly digest** - A summary of activity across your organization, with per-project controls.
+- **Data pipeline errors** - Alerts when destinations or batch exports fail, with a configurable failure rate threshold.
+- **Issue assigned** - Notifies you when an [Error Tracking](/docs/error-tracking) issue is assigned to you or your role.
+- **Error Tracking weekly digest** - A weekly summary of exceptions across your projects, sent every Monday.
+- **Comment mentions** - Notifies you when someone mentions you in a discussion.
+- **Private API key exposure** - Alerts when private API keys are publicly exposed.
+- **Materialized view sync failures** - Alerts when a materialized view fails to sync.
+
+### Error Tracking weekly digest
+
+The Error Tracking weekly digest sends a weekly email every Monday summarizing exceptions caught across your projects. The email is organized by organization, with a section for each enabled project.
+
+You can select which projects to include in the digest under [**Notifications**](https://us.posthog.com/settings/user#notifications). If you haven't selected any projects, PostHog automatically picks the project with the most exceptions on the first digest run. Once you manually select projects, this automatic selection won't happen.
 
 ## Theming and customization