Re-enable monaco horizontal scroll bars.

Like all things LLM and Monaco, the key here is to delete things
that aren't default until things get better. The scrollbars don't
show up because they aren't necessary, and, when the horizontal
ones are necessary, they now show up.

I'm still seeing two bugs:

1. If you click into the diff the first time on some line, especially
if it's the second diff block, Monaco jumps to a different area. This
is kind of terrible and annoying.

2. My touchpad should let me scroll right/left as well as vertical, but
I'm only getting vertical scrolling in this mode.
diff --git a/webui/src/web-components/sketch-monaco-view.ts b/webui/src/web-components/sketch-monaco-view.ts
index 6e783fa..03b6744 100644
--- a/webui/src/web-components/sketch-monaco-view.ts
+++ b/webui/src/web-components/sketch-monaco-view.ts
@@ -68,17 +68,6 @@
     height: 100%;
   }
   
-  // /* Custom font stack - ensure we have good monospace fonts */
-  // .monaco-editor .view-lines,
-  // .monaco-editor .view-line,
-  // .monaco-editor-pane,
-  // .monaco-editor .inputarea {
-  //   font-family: "Menlo", "Monaco", "Consolas", "Courier New", monospace !important;
-  //   font-size: 13px !important;
-  //   font-feature-settings: "liga" 0, "calt" 0 !important;
-  //   line-height: 1.5 !important;
-  // }
-  
   /* Ensure light theme colors */
   .monaco-editor, .monaco-editor-background, .monaco-editor .inputarea.ime-input {
     background-color: var(--monaco-editor-bg, #ffffff) !important;
@@ -87,26 +76,6 @@
   .monaco-editor .margin {
     background-color: var(--monaco-editor-margin, #f5f5f5) !important;
   }
-  
-  /* Hide all scrollbars completely */
-  .monaco-editor .scrollbar,
-  .monaco-editor .scroll-decoration,
-  .monaco-editor .invisible.scrollbar,
-  .monaco-editor .slider,
-  .monaco-editor .vertical.scrollbar,
-  .monaco-editor .horizontal.scrollbar {
-    display: none !important;
-    visibility: hidden !important;
-    width: 0 !important;
-    height: 0 !important;
-  }
-  
-  /* Ensure content area takes full width/height without scrollbar space */
-  .monaco-editor .monaco-scrollable-element {
-    /* Remove any padding/margin that might be reserved for scrollbars */
-    padding-right: 0 !important;
-    padding-bottom: 0 !important;
-  }
 `;
 
 // Configure Monaco to use local workers with correct relative paths
@@ -710,24 +679,19 @@
           theme: "vs", // Always use light mode
           renderSideBySide: !this.inline,
           ignoreTrimWhitespace: false,
-          renderOverviewRuler: false, // Disable the overview ruler
           scrollbar: {
-            vertical: "hidden",
-            horizontal: "hidden",
-            handleMouseWheel: false, // Let outer scroller eat the wheel
-            useShadows: false, // Disable scrollbar shadows
-            verticalHasArrows: false, // Remove scrollbar arrows
-            horizontalHasArrows: false, // Remove scrollbar arrows
-            verticalScrollbarSize: 0, // Set scrollbar track width to 0
-            horizontalScrollbarSize: 0, // Set scrollbar track height to 0
+            // Ideally we'd handle the mouse wheel for the horizontal scrollbar,
+            // but there doesn't seem to be that option. Setting
+            // alwaysConsumeMousewheel false and handleMouseWheel true didn't
+            // work for me.
+            handleMouseWheel: false,
           },
-          minimap: { enabled: false },
-          overviewRulerLanes: 0,
+          renderOverviewRuler: false, // Disable overview ruler
           scrollBeyondLastLine: false,
           // Focus on the differences by hiding unchanged regions
           hideUnchangedRegions: {
             enabled: true, // Enable the feature
-            contextLineCount: 3, // Show 3 lines of context around each difference
+            contextLineCount: 5, // Show 3 lines of context around each difference
             minimumLineCount: 3, // Hide regions only when they're at least 3 lines
             revealLineCount: 10, // Show 10 lines when expanding a hidden region
           },