set non-transparent colors for light mode, fix fuzzy letters issue with ghost prompt

public/themes/light.css

@@ -9,8 +9,8 @@
     --app-accent-color: rgb(75, 166, 57);
     --app-accent-bg-color: rgba(75, 166, 57, 0.2);
     --app-text-color: rgb(0, 0, 0);
-    --app-text-primary-color: rgb(0, 0, 0, 0.9);
-    --app-text-secondary-color: rgb(0, 0, 0, 0.7);
+    --app-text-primary-color: rgb(23, 23, 23);
+    --app-text-secondary-color: rgb(76, 76, 76);
     --app-border-color: rgb(139 145 138);
     --app-panel-bg-color: rgb(224, 224, 224);
     --app-panel-bg-color-dev: rgb(224, 224, 224);

src/app/workspace/cmdinput/textareainput.tsx

@@ -660,7 +660,7 @@ class TextAreaInput extends React.Component<{ screen: Screen; onHeightChange: ()
                         className="textarea-ghost"
                         style={{ height: computedInnerHeight, minHeight: computedInnerHeight, fontSize: termFontSize }}
                     >
-                        {`${curLine}${primaryAutocompleteSuggestion}`}
+                        {`${"\xa0".repeat(curLine.length)}${primaryAutocompleteSuggestion}`}
                     </div>
                 </If>
                 <textarea