Add paint feedback strategy planner

docs/modernization/roadmap.md

@@ -862,6 +862,12 @@ nested passes, texture I/O or blits inside a pass, and unclosed passes. It
 also validates executable command dependencies, including shader-before-uniform
 and shader-plus-mesh before draw within each render pass, and rejects invalid
 texture/sampler bind slots in malformed recorded streams.
+The renderer-neutral API now also plans complex paint feedback strategies for
+future stroke/layer compositing work: framebuffer-fetch-capable backends can
+read destination color directly, while other backends must use ping-pong render
+targets backed by texture copy or render-target blit support. This is exposed
+through `pano_cli plan-paint-feedback` and tracked by DEBT-0036 until the live
+paint renderer consumes the plan.
 The existing renderer classes are not yet fully
 behind the renderer interfaces.
 
@@ -1107,7 +1113,10 @@ Results:
   render-pass clear/scissor/depth/blend/shader-uniform/texture/sampler-bind/
   upload/texture-copy/readback/frame-capture/blit command capture, draw
   mesh-input capture, explicit draw-range capture, and invalid catalog
-  rejection.
+  rejection. The same suite now covers complex paint feedback planning for
+  framebuffer-fetch backends, ping-pong texture-copy/blit fallbacks, simple
+  no-feedback blends, invalid render-target usage, unsupported backends, and
+  depth-target rejection.
 - `pp_paint_renderer_compositor_tests` passed.
 - `pp_ui_core_color_tests` passed.
 - `pp_ui_core_layout_value_tests` passed.