webui: add setting for first-line chat titles (#21797)

* webui: add setting for first-line chat titles

Add an opt-in setting (`titleGenerationUseFirstLine`) to use the first
non-empty line of a prompt as the generated conversation title.

Previously, the complete multi-line prompt was being used, which created
long titles for complex queries. Coupled with
"Ask for confirmation before changing conversation title", the dialog
would overflow.

* Update tools/server/webui/src/lib/utils/text.ts

Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>

* Update tools/server/webui/src/lib/utils/text.ts

Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>

* webui: Run build to update the bundle

As requested in:
https://github.com/ggml-org/llama.cpp/pull/21797#pullrequestreview-4094935065

* webui: Fix missing import for NEWLINE_SEPARATOR

---------

Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>

tools/server/webui/src/lib/utils/index.ts

@@ -55,7 +55,7 @@ export {
 
 // File preview utilities
 export { getFileTypeLabel } from './file-preview';
-export { getPreviewText } from './text';
+export { getPreviewText, generateConversationTitle } from './text';
 
 // File type utilities
 export {

tools/server/webui/src/lib/utils/text.ts

@@ -1,3 +1,5 @@
+import { NEWLINE_SEPARATOR } from '$lib/constants';
+
 /**
  * Returns a shortened preview of the provided content capped at the given length.
  * Appends an ellipsis when the content exceeds the maximum.
@@ -5,3 +7,16 @@
 export function getPreviewText(content: string, max = 150): string {
 	return content.length > max ? content.slice(0, max) + '...' : content;
 }
+
+/**
+ * Generates a single-line title from a potentially multi-line prompt.
+ * Uses the first non-empty line if `useFirstLine` is true.
+ */
+export function generateConversationTitle(content: string, useFirstLine: boolean = false): string {
+	if (useFirstLine) {
+		const firstLine = content.split(NEWLINE_SEPARATOR).find((line) => line.trim().length > 0);
+		return firstLine ? firstLine.trim() : content.trim();
+	}
+
+	return content.trim();
+}