webui: implement pinned conversations support (#21387)

* webui: implement pinned conversations support

* webui: linter/prettier pass

* Fix the unused handleMobileSidebarItemClick from the component.

* the search should find pinned conversations as well

Co-authored-by: Pascal <admin@serveurperso.com>

---------

Co-authored-by: Pascal <admin@serveurperso.com>

tools/ui/src/lib/services/database.service.ts

@@ -344,6 +344,22 @@ export class DatabaseService {
 	 *
 	 */
 
+	/**
+	 * Toggles the pinned status of a conversation.
+	 *
+	 * @param id - Conversation ID
+	 * @returns The new pinned status
+	 */
+	static async toggleConversationPin(id: string): Promise<boolean> {
+		const conversation = await db.conversations.get(id);
+		if (!conversation) {
+			throw new Error(`Conversation ${id} not found`);
+		}
+		const newPinnedState = !conversation.pinned;
+		await this.updateConversation(id, { pinned: newPinnedState });
+		return newPinnedState;
+	}
+
 	/**
 	 * Updates the conversation's current node (active branch).
 	 * This determines which conversation path is currently being viewed.