Feature: Add user preference to disable notifications for own actions

[timothyfroehlich]

While the default behavior should be to send notifications to users for their own actions (Issue #849), some users may find this redundant. We should provide a way for users to opt-out of this behavior in their notification settings.

Proposed Changes

1. Update Database Schema: Add a new boolean column notify_on_own_actions to the notification_preferences table in src/server/db/schema.ts, defaulting to true.
2. Update Preferences UI: Add a toggle in the user settings/notifications page to allow users to disable this preference.
3. Update Notification Logic:
   • Modify createNotification in src/lib/notifications.ts to always include the actor in the initial recipientIds set (if they are a watcher/owner).
   • In the loop where preferences are checked, use the new notify_on_own_actions preference to decide whether to actually send the notification to the actor.

Relevant Files

• src/server/db/schema.ts: Schema for notification preferences.
• src/lib/notifications.ts: Logic for filtering recipients based on preferences.
• src/app/(app)/settings/notifications/page.tsx: UI for managing preferences.

[timothyfroehlich]

Already implemented: suppress_own_actions preference exists in DB schema, settings UI, and notification logic. —Claude