fix(app): withhold Terminal from a teammate's channel and say where its terminals open

.lane/memory/apps/app/src/channel.tsx/01M5JRPBHXDKJV5CM9KV4R35YH-only-this-host-s-own-local-c.md

@@ -0,0 +1,12 @@
+---
+id: 01M5JRPBHXDKJV5CM9KV4R35YH
+anchor: function Channel
+created: 2026-10-22T21:36:22Z
+norm: '1'
+sig: eaede8e100f39ef4
+body_hash: d29a81f75aaca2c5
+raw_hash: 24baf292b9594958
+lines: 305-439
+---
+
+only this host's own local channels offer Terminal; saved Terminal tabs elsewhere show where terminals open instead of an empty pane

apps/app/src/channel.tsx

@@ -334,9 +334,10 @@ export function Channel(
 	}, [channel.id]);
 
 	// Shells live on this host, so only its own channels have them; reconnecting may follow a reload.
+	const elsewhere = remote || place.kind !== "local";
 	const [shells, setShells] = useState<TerminalShell[]>();
 	useEffect(() => {
-		if (remote || place.kind !== "local") return;
+		if (elsewhere) return;
 		let live = true;
 		const load = () => {
 			host.request<TerminalShell[]>({ op: "terminals", channel: channel.id }).then(
@@ -352,7 +353,7 @@ export function Channel(
 			live = false;
 			off();
 		};
-	}, [channel.id, remote, place.kind]);
+	}, [channel.id, elsewhere]);
 
 	const opener = useRef<() => void>(undefined);
 	useEffect(() => {
@@ -384,6 +385,7 @@ export function Channel(
 			changed={changed}
 			opener={opener}
 			shells={shells}
+			terminals={!elsewhere}
 			actions={<ChannelAccess channel={channel} user={user} />}
 			render={(data, uid, active, update) => {
 				if (uid === CHAT) {
@@ -406,6 +408,18 @@ export function Channel(
 					return <Diff channel={channel} chat={data.chat} user={user} active={active} />;
 				}
 				if (data.type !== "terminal") return null;
+				// Tabs saved before Terminal was withheld here still open, so they say why they're empty.
+				if (elsewhere) {
+					return (
+						<section className="grid h-full min-h-0 place-items-center bg-background px-4 text-center text-sm text-muted-foreground">
+							{place.kind === "cloud"
+								? "This cloud channel's shell is in its container, so terminals don't open here."
+								: place.kind === "hosted"
+								? `This channel runs on ${place.service}, which doesn't open terminals.`
+								: `Terminals open on the channel's host, ${channel.host}, and only for its owner.`}
+						</section>
+					);
+				}
 				return (
 					<Terminal
 						channel={channel.id}

apps/app/src/layout/layout.tsx

@@ -108,12 +108,15 @@ type Props = {
 	opener?: { current?: () => void };
 	/** Running shells no client shows; each without a tab here opens as a background Terminal tab. */
 	shells?: { terminal: string; chat?: number }[];
+	/** Whether this host opens the channel's shells; only then is Terminal offered. */
+	terminals: boolean;
 };
 
 const MIN = 350;
 const CHAT_MIN = 450;
 // The old app also offered Plan, Browse, and Browser Preview; they return when their backends do.
 const CHOICES: Choice[] = ["chat", "diff", "terminal"];
+const SHELLESS: Choice[] = ["chat", "diff"];
 const ICONS: Record<Kind, Icon> = {
 	blank: IconSplitView,
 	chat: IconMessage,
@@ -193,14 +196,20 @@ function focus(uid: string) {
 	document.querySelector<HTMLElement>(`[data-layout-tab="${CSS.escape(uid)}"]`)?.focus();
 }
 
-function Blank({ item, onChoose }: { item: Item; onChoose: (choice: Choice) => void }) {
+function Blank(
+	{ item, choices, onChoose }: {
+		item: Item;
+		choices: Choice[];
+		onChoose: (choice: Choice) => void;
+	},
+) {
 	const Icon = item.icon;
 
 	if (item.kind === "blank") {
 		return (
 			<div className="flex h-full min-h-0 items-center justify-center px-4 contain-content">
 				<div className="scrollbar-muted flex max-h-full min-w-0 flex-col overflow-y-auto py-2 contain-style">
-					{CHOICES.map((choice) => {
+					{choices.map((choice) => {
 						const Icon = ICONS[choice];
 						return (
 							<Button
@@ -231,7 +240,7 @@ function Blank({ item, onChoose }: { item: Item; onChoose: (choice: Choice) => v
 	);
 }
 
-function Add({ onAdd }: { onAdd: (choice: Choice) => void }) {
+function Add({ choices, onAdd }: { choices: Choice[]; onAdd: (choice: Choice) => void }) {
 	return (
 		<DropdownMenu>
 			<DropdownMenuTrigger
@@ -253,7 +262,7 @@ function Add({ onAdd }: { onAdd: (choice: Choice) => void }) {
 				className="scrollbar-muted max-h-80 w-56 overflow-y-auto"
 			>
 				<DropdownMenuGroup>
-					{CHOICES.map((choice) => {
+					{choices.map((choice) => {
 						const Icon = ICONS[choice];
 						return (
 							<DropdownMenuItem key={choice} onClick={() => onAdd(choice)}>
@@ -573,6 +582,7 @@ type BarProps = {
 	onFork: (side: "right" | "bottom") => void;
 	can: (side: "right" | "bottom") => boolean;
 	onSelect: (id: string) => void;
+	choices: Choice[];
 	onAdd: (choice: Choice) => void;
 	onClose: (id: string) => void;
 	onRename: (id: string, name: string) => void;
@@ -595,6 +605,7 @@ function Bar({
 	onFork,
 	can,
 	onSelect,
+	choices,
 	onAdd,
 	onClose,
 	onRename,
@@ -677,7 +688,7 @@ function Bar({
 			</div>
 			{more && <More pane={pane} items={items} onSelect={onSelect} />}
 			{actions}
-			<Add onAdd={onAdd} />
+			<Add choices={choices} onAdd={onAdd} />
 			{!flat && <Tools split={onFork} can={can} />}
 		</div>
 	);
@@ -694,7 +705,8 @@ type PaneProps = BarProps & {
 };
 
 function Pane(props: PaneProps) {
-	const { pane, items, meta, focused, drop, header, render, onFocus, onChoose, onUpdate } = props;
+	const { pane, items, meta, focused, drop, header, render, choices, onFocus, onChoose, onUpdate } =
+		props;
 	const hover = drop?.kind === "pane" ? drop : undefined;
 	const blocked = !!hover?.side && !hover.valid;
 
@@ -731,7 +743,13 @@ function Pane(props: PaneProps) {
 								active ? "" : "pointer-events-none invisible"
 							}`}
 						>
-							{node || <Blank item={item} onChoose={(choice) => onChoose(id, choice)} />}
+							{node || (
+								<Blank
+									item={item}
+									choices={choices}
+									onChoose={(choice) => onChoose(id, choice)}
+								/>
+							)}
 						</div>
 					);
 				})}
@@ -1038,6 +1056,7 @@ export function Layout(props: Props) {
 			onFork: (side: "right" | "bottom") => add(pane, "blank", side),
 			can: (side: "right" | "bottom") => allow(pane, side),
 			onSelect: (uid: string) => choose(uid, pane),
+			choices: props.terminals ? CHOICES : SHELLESS,
 			onAdd: (choice: Choice) => add(pane, choice),
 			onClose: close,
 			onRename: rename,