feat(editor): Implement pixel-based scrolling for the Editor (#418)

Refactors the Editor's scrolling implementation to be pixel-based instead of line-based. This provides smoother and more granular scrolling, which works more consistently across different input devices (like trackpads).

- The `Action::Scroll` variant now takes `pixels: f32`.
- The `Editor` now processes scroll actions using pixel values directly.
- Examples have been updated to reflect the new scrolling behavior.

src/edit/editor.rs

@@ -858,11 +858,11 @@ impl<'buffer> Edit<'buffer> for Editor<'buffer> {
                     }
                 }
             }
-            Action::Scroll { lines } => {
+            Action::Scroll { pixels } => {
                 self.with_buffer_mut(|buffer| {
                     let mut scroll = buffer.scroll();
                     //TODO: align to layout lines
-                    scroll.vertical += lines as f32 * buffer.metrics().line_height;
+                    scroll.vertical += pixels;
                     buffer.set_scroll(scroll);
                 });
             }

src/edit/mod.rs

@@ -20,7 +20,7 @@ pub use self::vi::*;
 mod vi;
 
 /// An action to perform on an [`Editor`]
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum Action {
     /// Move the cursor with some motion
     Motion(Motion),
@@ -58,9 +58,9 @@ pub enum Action {
         x: i32,
         y: i32,
     },
-    /// Scroll specified number of lines
+    /// Scroll specified number of pixels
     Scroll {
-        lines: i32,
+        pixels: f32,
     },
 }