fix(chat): address fourth round of PR review feedback

- Fix ReadOnlyToolCall lineRange: disk read always returns the whole
  file so always display 1–N (trimming trailing newline before counting)
- Fix Shiki fallback to render escaped plain text instead of empty
  strings when codeToHtml fails for the "text" language itself
- Trim trailing newline before computing lineCount in ShowCode so files
  ending with \n do not trigger isOverflowing one line early

Author: michalkopanski

apps/desktop/src/renderer/components/Chat/ChatInterface/components/ReadOnlyToolCall/ReadOnlyToolCall.tsx

@@ -90,15 +90,9 @@ export function ReadOnlyToolCall({
 
 	const lineRange = hasFileContent
 		? (() => {
-				const startLine =
-					Number(
-						args.startLine ?? args.start_line ?? args.offset ?? args.from ?? 1,
-					) || 1;
-				const lineCount = fileContent.split("\n").length;
-				const endLine = startLine + lineCount - 1;
-				return startLine === 1 && endLine === lineCount
-					? `1–${lineCount}`
-					: `${startLine}–${endLine}`;
+				// The disk read always returns the whole file, so report 1–N
+				const lineCount = fileContent.trimEnd().split("\n").length;
+				return `1–${lineCount}`;
 			})()
 		: null;
 

packages/ui/src/components/ai-elements/code-block.tsx

@@ -80,7 +80,12 @@ export async function highlightCode(
 		]);
 	} catch {
 		if (language === ("text" as BundledLanguage)) {
-			return ["", ""];
+			const escaped = code
+				.replace(/&/g, "&")
+				.replace(/</g, "&lt;")
+				.replace(/>/g, "&gt;");
+			const html = `<pre><code>${escaped}</code></pre>`;
+			return [html, html];
 		}
 		// Unknown/unsupported language — fall back to plain text
 		return highlightCode(

packages/ui/src/components/ai-elements/show-code.tsx

@@ -80,7 +80,7 @@ export function ShowCode({
 	const [isCopied, setIsCopied] = useState(false);
 	const [isExpanded, setIsExpanded] = useState(false);
 
-	const lineCount = code.split("\n").length;
+	const lineCount = code.trimEnd().split("\n").length;
 	const isOverflowing = lineCount > maxLines;
 
 	const handleCopy = async () => {