Clippy fixes

src/main.rs

@@ -1,4 +1,4 @@
-use anyhow::{Context, Result};
+use anyhow::Result;
 use std::thread;
 use std::time::Duration;
 use x11rb::wrapper::ConnectionExt as _;

src/wallpaper.rs

@@ -27,7 +27,7 @@ pub struct PreparedWallpaper {
 
 /// Convert RGBA byte order to BGRA.
 ///
-/// Image libraries produce RGBA, but X11 TrueColor visuals typically use
+/// Image libraries produce RGBA, but X11 `TrueColor` visuals typically use
 /// BGRX/BGRA byte order on little-endian systems.
 /// Swap red and blue channels to match the server’s native pixel layout.
 /// Without this conversion, colors appear incorrect.