chat : add keyboard shortcut to jump between conversation tabs

Shift+Cmd/Ctrl+Left/Right cycles the open tabs, mirroring the existing
Shift+Cmd/Ctrl+Up/Down conversation navigation.

Assisted-by: pi

tools/ui/src/lib/hooks/use-keyboard-shortcuts.svelte.ts

@@ -9,6 +9,8 @@ interface KeyboardShortcutsCallbacks {
 	deleteActiveConversation?: () => void;
 	navigateToPrevConversation?: () => void;
 	navigateToNextConversation?: () => void;
+	navigateToPrevTab?: () => void;
+	navigateToNextTab?: () => void;
 	toggleSidebar?: () => void;
 }
 
@@ -82,6 +84,16 @@ export function useKeyboardShortcuts(callbacks: KeyboardShortcutsCallbacks) {
 			event.preventDefault();
 			callbacks.navigateToNextConversation?.();
 		}
+
+		if (isCmdOrCtrl && event.shiftKey && event.key === KeyboardKey.ARROW_LEFT) {
+			event.preventDefault();
+			callbacks.navigateToPrevTab?.();
+		}
+
+		if (isCmdOrCtrl && event.shiftKey && event.key === KeyboardKey.ARROW_RIGHT) {
+			event.preventDefault();
+			callbacks.navigateToNextTab?.();
+		}
 	}
 
 	return { handleKeydown };

tools/ui/src/routes/+layout.svelte

@@ -76,6 +76,27 @@
 		}
 	}
 
+	function navigateToTab(direction: -1 | 1) {
+		// only makes sense with conversation tabs enabled
+		if (!settingsStore.config.conversationTabs) return;
+
+		const openTabs = tabsStore.openTabs;
+
+		if (openTabs.length === 0) return;
+
+		const activeId = page.params.id ?? NEW_CHAT_TAB_ID;
+		const idx = openTabs.indexOf(activeId);
+		// active tab not in list (e.g. a non-chat route): start from an edge
+		const targetIdx =
+			idx === -1
+				? direction === 1
+					? 0
+					: openTabs.length - 1
+				: (idx + direction + openTabs.length) % openTabs.length;
+
+		void tabsStore.activate(openTabs[targetIdx]);
+	}
+
 	function navigateToConversation(direction: -1 | 1) {
 		const allConvs = conversationsStore.conversations;
 
@@ -120,7 +141,9 @@
 	const { handleKeydown } = useKeyboardShortcuts({
 		editActiveConversation: () => chatSidebar?.editActiveConversation?.(),
 		navigateToNextConversation: () => navigateToConversation(1),
-		navigateToPrevConversation: () => navigateToConversation(-1)
+		navigateToNextTab: () => navigateToTab(1),
+		navigateToPrevConversation: () => navigateToConversation(-1),
+		navigateToPrevTab: () => navigateToTab(-1)
 	});
 
 	function checkApiKey() {