Ripple and Glitch are gone; Crt stays

The user tried them live and wants them removed entirely: the builtins,
their levels, config keys and leader paths (tR, tg), their slots in the
built-in chain, their shaders (source and prebuilt), EffectCode paths, and
on macOS their scene flags (pardes.h), the Metal kernel's coordinate warps
and the Swift pointer mapping that mirrored them. Docs say so (decision 8
in docs/render-pipeline.md); config.md documents Crt's levels, Shader and
ShaderAnimation instead.

Shared files touched: macos.zig (flags). Not touched: pardes.zig,
Messages.zig, mouse.zig, gui.zig, detached/*.

1 files changed, 8 insertions, 7 deletions

diff --git a/docs/config.md b/docs/config.md
index 9c51f329..16fd59e5 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -513,18 +513,19 @@ immediately and remains the one authoritative geometry. DOM web intentionally
 does not expose these builtins: its renderer is selectable HTML/CSS and has no
 canvas or shader stage.
 
-The scene effects are independent switches and can be combined:
+The scene effect is `Crt`, at a level from 0 (off) to 3; `on` is 2:
 
 ```text
 Crt
-Ripple
-Glitch
+Crt 3
 ```
 
-They share one full-scene shader pass in SDL and macOS. With all three off the
-pass is bypassed. CRT works in linear light with restrained scanlines, mask,
-bloom, curvature, and noise rather than remapping the theme to a strong fixed
-palette; Ripple and Glitch primarily perturb sample coordinates.
+The SDL GUI runs it as the bundled pass of its post chain, which also takes
+Shadertoy files written for ghostty (`Shader ~/crt.glsl`, `Shader off`), and
+`ShaderAnimation off|on|always` says when the chain animates on its own. With
+the chain empty the pass is bypassed. CRT works in linear light with restrained
+scanlines, mask, bloom and vignette, and no curvature, so clicks land where
+they are drawn.
 
 `EffectCode PanelAscii` or `EffectCode Crt` lists the current backend's
 build-embedded source paths under `/virtual`. Look opens each full file;