tombstone gate all user paths; cleanup deletes late follower rows; spa self-delete to /; adr 0016 + purge comment

crates/adapters/sqlite/tests/account_purge_test.rs

@@ -696,6 +696,14 @@ async fn tombstone_cleanup_removes_rows_older_than_retention_and_keeps_younger_o
     assert_eq!(count_for(&pool, "users", "id", &s.user).await, 1);
     assert_eq!(unfinished().await, before);
 
+    // A Follow that reached the shared inbox after the purge left a row.
+    exec(
+        &pool,
+        "INSERT INTO ap_followers (local_user_id, remote_actor_url, status, created_at)
+         VALUES (?, 'https://late.example/users/zed', 'pending', '2026-01-01T00:00:00Z')",
+        &[&alice],
+    )
+    .await;
     // Once they finish, the cleanup takes the tombstone and the history.
     exec(&pool, "UPDATE event_queue SET status = 'done'", &[]).await;
     let removed = p
@@ -712,6 +720,11 @@ async fn tombstone_cleanup_removes_rows_older_than_retention_and_keeps_younger_o
         left.iter().all(|p| !p.contains(&alice)),
         "no history of the user remains: {left:?}"
     );
+    assert_eq!(
+        count_for(&pool, "ap_followers", "local_user_id", &s.user).await,
+        0,
+        "late shared-inbox follower row"
+    );
     assert_eq!(
         count_for(&pool, "ap_local_actors", "user_id", &s.user).await,
         0