Add renderer shader uniform command

docs/modernization/roadmap.md

@@ -724,9 +724,10 @@ Results:
   validation, texture-upload byte-count validation, frame-capture byte-size and
   command-order validation, render-target blit validation, texture-slot binding
   validation, blend-state validation, scissor-state validation,
-  backend-neutral resource factory validation, recording
-  scissor/depth/blend/texture/sampler-bind/upload/readback/frame-capture/blit
-  command capture, draw mesh-input capture, and invalid catalog rejection.
+  shader-uniform write validation, backend-neutral resource factory validation,
+  recording scissor/depth/blend/shader-uniform/texture/sampler-bind/upload/
+  readback/frame-capture/blit command capture, draw mesh-input capture, and
+  invalid catalog rejection.
 - `pp_paint_renderer_compositor_tests` passed.
 - `pp_ui_core_color_tests` passed.
 - `pp_ui_core_layout_value_tests` passed.
@@ -822,18 +823,19 @@ Results:
 - `pp_renderer_api` now includes a headless `RecordingRenderDevice` with strict
   renderer-owned resource factory and
   command-order/scissor-state/depth-state/blend-state/texture-bind/
-  sampler-bind/texture-upload/readback/frame-capture/blit validation; it
-  creates validated textures, render targets, shaders, meshes, and readback
-  buffers, then records commands, trace markers, scissor state, depth state,
-  blend state, texture/sampler binds, draw mesh inputs, uploads/readbacks,
-  frame captures, and render-target blits, giving automation a backend-neutral
-  render path that does not require a window or GL context.
+  sampler-bind/shader-uniform/texture-upload/readback/frame-capture/blit
+  validation; it creates validated textures, render targets, shaders, meshes,
+  and readback buffers, then records commands, trace markers, scissor state,
+  depth state, blend state, shader uniform writes, texture/sampler binds, draw
+  mesh inputs, uploads/readbacks, frame captures, and render-target blits,
+  giving automation a backend-neutral render path that does not require a
+  window or GL context.
 - `pano_cli record-render` exercises that headless recording renderer and emits
   JSON command counts, resource creation counts, target dimensions, backend
   name, trace/draw summary, and draw vertex/index totals, scissor/depth/
-  blend-state plus texture/sampler-bind/upload/readback/frame-capture/blit
-  command/byte totals for agent automation, with an expected-failure smoke for
-  oversized render/readback targets.
+  blend-state plus shader-uniform/texture/sampler-bind/upload/readback/
+  frame-capture/blit command/byte totals for agent automation, with an
+  expected-failure smoke for oversized render/readback targets.
 - `pano_cli simulate-document-history` exercises pure document history
   apply/undo/redo behavior and emits JSON layer/frame/history state for agent
   automation.