efficient rendering of log view, node reversal

src/render/render.c

@@ -22,7 +22,9 @@ fn rn_cmd_t *rn_get_cmd(rn_cmd_kind_t kind) {
 
 fn rn_vertex_t *rn_push_vertex(rn_cmd_t *cmd, u32 count) {
     rn_vertex_t *result = cmd->vertex + cmd->len;
+    assert(rn->cap >= rn->len + count);
     rn->len += count;
+
     cmd->len += count;
     return result;
 }