feat: add keyboard shortcuts for playground and edit last user message

Closes #1008

- Ctrl/Cmd+Enter: run/submit in Playground Chat and Completions
- Ctrl/Cmd+Shift+A: add message in Playground Chat (mirrors Add button, auto-toggles role)
- Ctrl/Cmd+Shift+X: toggle user/assistant role in Playground Chat
- Ctrl/Cmd+E: edit last user message from anywhere in the main chat

Playground shortcuts handled locally via svelte:window in each component.
Global layout handler covers Ctrl/Cmd+E using getElementsByClassName pattern.

src/lib/components/chat/ShortcutsModal.svelte

@@ -97,6 +97,11 @@
 						<!-- {$i18n.t('Only active when the chat input is in focus.')} -->
 						<!-- {$i18n.t('Only active when the chat input is in focus and an LLM is generating a response.')} -->
 						<!-- {$i18n.t('Only can be triggered when the chat input is in focus.')} -->
+						<!-- {$i18n.t('Edit Last User Message')} -->
+						<!-- {$i18n.t('Playground')} -->
+						<!-- {$i18n.t('Run')} -->
+						<!-- {$i18n.t('Add Message')} -->
+						<!-- {$i18n.t('Toggle Role')} -->
 						{#each items as shortcut}
 							<div class="col-span-1 flex items-start">
 								<ShortcutItem {shortcut} {isMac} />

src/lib/components/playground/Chat.svelte

@@ -288,6 +288,24 @@
 		toast.success($i18n.t('Chat exported successfully'));
 	};
 
+	const handleKeydown = (event: KeyboardEvent) => {
+		const mod = event.ctrlKey || event.metaKey;
+
+		if (mod && !event.shiftKey && event.key === 'Enter') {
+			if (!loading) {
+				event.preventDefault();
+				submitHandler();
+			}
+		} else if (mod && event.shiftKey && event.key.toLowerCase() === 'a') {
+			event.preventDefault();
+			addHandler();
+			role = role === 'user' ? 'assistant' : 'user';
+		} else if (mod && event.shiftKey && event.key.toLowerCase() === 'x') {
+			event.preventDefault();
+			role = role === 'user' ? 'assistant' : 'user';
+		}
+	};
+
 	onMount(async () => {
 		if ($user?.role !== 'admin') {
 			await goto('/');
@@ -304,6 +322,8 @@
 	});
 </script>
 
+<svelte:window on:keydown={handleKeydown} />
+
 <div class=" flex flex-col justify-between w-full overflow-y-auto h-full">
 	<div class="mx-auto w-full md:px-0 h-full relative">
 		<div class=" flex flex-col h-full px-3.5">

src/lib/components/playground/Completions.svelte

@@ -103,6 +103,17 @@
 		}
 	};
 
+	const handleKeydown = (event: KeyboardEvent) => {
+		const mod = event.ctrlKey || event.metaKey;
+
+		if (mod && !event.shiftKey && event.key === 'Enter') {
+			if (!loading) {
+				event.preventDefault();
+				submitHandler();
+			}
+		}
+	};
+
 	onMount(async () => {
 		if ($user?.role !== 'admin') {
 			await goto('/');
@@ -119,6 +130,8 @@
 	});
 </script>
 
+<svelte:window on:keydown={handleKeydown} />
+
 <div class=" flex flex-col justify-between w-full overflow-y-auto h-full">
 	<div class="mx-auto w-full md:px-0 h-full">
 		<div class=" flex flex-col h-full px-4">

src/lib/shortcuts.ts

@@ -40,7 +40,13 @@ export enum Shortcut {
 	REGENERATE_RESPONSE = 'regenerateResponse',
 	COPY_LAST_CODE_BLOCK = 'copyLastCodeBlock',
 	COPY_LAST_RESPONSE = 'copyLastResponse',
-	STOP_GENERATING = 'stopGenerating'
+	STOP_GENERATING = 'stopGenerating',
+	EDIT_LAST_MESSAGE = 'editLastMessage',
+
+	//Playground
+	PLAYGROUND_SUBMIT = 'playgroundSubmit',
+	PLAYGROUND_ADD_MESSAGE = 'playgroundAddMessage',
+	PLAYGROUND_TOGGLE_ROLE = 'playgroundToggleRole'
 }
 
 export const shortcuts: ShortcutRegistry = {
@@ -164,5 +170,27 @@ export const shortcuts: ShortcutRegistry = {
 		name: 'Copy Last Code Block',
 		keys: ['mod', 'shift', ';'],
 		category: 'Message'
+	},
+	[Shortcut.EDIT_LAST_MESSAGE]: {
+		name: 'Edit Last User Message',
+		keys: ['mod', 'E'],
+		category: 'Message'
+	},
+
+	//Playground
+	[Shortcut.PLAYGROUND_SUBMIT]: {
+		name: 'Run',
+		keys: ['mod', 'Enter'],
+		category: 'Playground'
+	},
+	[Shortcut.PLAYGROUND_ADD_MESSAGE]: {
+		name: 'Add Message',
+		keys: ['mod', 'shift', 'A'],
+		category: 'Playground'
+	},
+	[Shortcut.PLAYGROUND_TOGGLE_ROLE]: {
+		name: 'Toggle Role',
+		keys: ['mod', 'shift', 'X'],
+		category: 'Playground'
 	}
 };

src/routes/(app)/+layout.svelte

@@ -311,6 +311,10 @@
 					console.log('Shortcut triggered: REGENERATE_RESPONSE');
 					event.preventDefault();
 					[...document.getElementsByClassName('regenerate-response-button')]?.at(-1)?.click();
+				} else if (isShortcutMatch(event, shortcuts[Shortcut.EDIT_LAST_MESSAGE])) {
+					console.log('Shortcut triggered: EDIT_LAST_MESSAGE');
+					event.preventDefault();
+					[...document.getElementsByClassName('edit-user-message-button')]?.at(-1)?.click();
 				}
 			});
 		};