Fix particle sizes, and add tools for comparing renderers

Particles: Direct3D 9's size limit evidently isn't the documented 64 pixels; unclamped (up to 2048) they match the client's renderer. A compare view shows the left half's scene over the right half, both renderers side by side; %TEMP%\t5de-renderer-view.txt switches views and %TEMP%\t5de-renderer-shaders\fixed_function.hlsl replaces the shaders while the client runs. The renderer process runs from a copy, so the program can be replaced meanwhile. The adapter recognizes only the textures and buffers it made (others reach the client renderer unchanged) and logs the others and render targets.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

include/t5de/protocol/channel.hpp

@@ -11,9 +11,10 @@ inline constexpr std::uint32_t version = 2;
 
 // Which part of the client's 3D view the renderer process draws (the client's own renderer draws all of it, under).
 enum class View : std::uint32_t {
-    Off,   // none
-    Split, // the right half, to compare with the client's renderer on the left
+    Off,     // none
+    Split,   // the right half, to compare with the client's renderer on the left
     Full,
+    Compare, // over the right half, the left half's scene: both renderers side by side, showing the same
 };
 
 // A shared memory section the adapter creates for each engine, named by the renderer process's `--channel <name>`