fix(db): enqueue artifact export on session_kind-only updates

session_kind is export-visible via the artifact manifest, but the
artifact_sessions_update_queue trigger's change-detection list did not
include it, so a session-kind-only update on an already-published
session left its manifest stale. Add the column to the trigger and pin
it with an export-queue test.

Author: mjacobs

internal/db/artifact_publication_test.go

@@ -1909,6 +1909,26 @@ func TestArtifactPublicationQueueIgnoresSessionBookkeepingUpdates(t *testing.T)
 	assert.Empty(t, artifactExportQueueIDs(t, database))
 }
 
+// TestArtifactPublicationQueueEnqueuesSessionKindOnlyUpdate pins
+// session_kind into the artifact_sessions_update_queue trigger's
+// change-detection list: the field is export-visible via the manifest, so a
+// session-kind-only update on an already-published session must re-enqueue
+// its export.
+func TestArtifactPublicationQueueEnqueuesSessionKindOnlyUpdate(t *testing.T) {
+	database := testDB(t)
+	seedArtifactOrigin(t, database)
+	require.NoError(t, database.UpsertSession(Session{
+		ID: "session", Project: "project", Machine: "local", Agent: "claude",
+	}))
+	clearArtifactExportQueue(t, database)
+
+	_, err := database.getWriter().Exec(
+		`UPDATE sessions SET session_kind = 'bg' WHERE id = 'session'`)
+	require.NoError(t, err)
+	assert.Equal(t, []string{"session"}, artifactExportQueueIDs(t, database),
+		"a session-kind-only update must re-enqueue the session for export")
+}
+
 // TestArtifactExportQueueStaysEmptyWithoutOrigin covers the deviation-1
 // origin gate: an archive that has never created or adopted an artifact
 // origin must never populate artifact_export_queue, regardless of how many

internal/db/db.go

@@ -2311,6 +2311,7 @@ WHEN (
     OLD.agent IS NOT NEW.agent OR
     OLD.agent_label IS NOT NEW.agent_label OR
     OLD.entrypoint IS NOT NEW.entrypoint OR
+    OLD.session_kind IS NOT NEW.session_kind OR
     OLD.first_message IS NOT NEW.first_message OR
     OLD.display_name IS NOT NEW.display_name OR
     OLD.session_name IS NOT NEW.session_name OR