feat: stats and achievements (#45)

### Explanation

_No response_

### Issue

Closes #39

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- [ ] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [ ] I have pinned the dependencies to a specific patch version.

### Style

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### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
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Reviewed-on: #45
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

src/lib/notifications/types.ts

@@ -4,6 +4,7 @@ export enum NotificationType {
   PERMISSION = "permission",
   CONNECTION = "connection",
   TASK_START = "task_start",
+  ACHIEVEMENT = "achievement",
 }
 
 export interface NotificationSound {
@@ -45,4 +46,10 @@ export const NOTIFICATION_SOUNDS: Record<NotificationType, NotificationSound> =
     phrase: "Working on it!",
     volume: 0.6,
   },
+  [NotificationType.ACHIEVEMENT]: {
+    type: NotificationType.ACHIEVEMENT,
+    filename: "achievement.mp3",
+    phrase: "Achievement Get~!",
+    volume: 0.8,
+  },
 };