Add renderer trace scope contract

docs/modernization/build-inventory.md

@@ -295,12 +295,13 @@ Known local toolchain state:
   render-pass-clear/scissor/depth/blend/shader-uniform/texture-bind/
   sampler-bind/draw/upload/mipmap-generation/texture-copy/readback/
   frame-capture/blit commands, draw mesh inputs, explicit draw ranges, and
-  records trace markers without a window or GL context.
+  records trace markers and scopes without a window or GL context.
 - `pano_cli record-render` exposes the recording renderer through JSON
   automation, including render-pass/depth-clear counts, scissor/depth/blend/
   shader-uniform/texture-bind/sampler-bind/upload/texture-copy/readback/
-  frame-capture/blit command and byte totals, backend resource creation counts,
-  plus draw descriptor vertex/index totals, and is covered by
+  frame-capture/blit command and byte totals, trace marker/scope counts,
+  backend resource creation counts, plus draw descriptor vertex/index totals,
+  and is covered by
   `pano_cli_record_render_smoke` plus
   `pano_cli_record_render_rejects_oversized_target`.
 - `pano_cli simulate-document-history` exposes `pp_document::DocumentHistory`