feat(ui): New tab always opens a new tab

apps/ui/src/keyboard/spine.ts

@@ -175,6 +175,7 @@ export function createKeyboardSpine(deps: {
 	registerLayoutCommand("tab.new", "New tab", ["open", "bridge"], () => ({
 		kind: "open",
 		path: "/",
+		fresh: true,
 	}));
 	registerGlobal("tab.close", "Close tab", ["close", "current"], () => {
 		deps.closeTab(deps.layout().activeTabId);

apps/ui/src/tab-keep-alive.test.tsx

@@ -40,12 +40,13 @@ const panelForView = (container: HTMLElement, viewId: string): HTMLElement => {
 afterEach(() => cleanup());
 
 describe("tab and pane commands on the real store", () => {
-	test("New tab on the Bridge tab keeps one tab with Bridge focused", async () => {
+	test("New tab on the Bridge tab opens a second Bridge tab and focuses it", async () => {
 		const { store } = mountApp("/");
 		await flush();
 		runCommand(store, "tab.new");
 		await flush();
-		expect(store.layout().tabs).toHaveLength(1);
+		expect(store.layout().tabs).toHaveLength(2);
+		expect(store.layout().activeTabId).toBe(tabIdAt(store, 1));
 		expect(store.view()).toBe("bridge");
 	});
 

apps/ui/src/window-layout.test.ts

@@ -64,6 +64,25 @@ describe("reduceLayout", () => {
 		expect(next.activeTabId).toBe(backlog?.id ?? "");
 	});
 
+	test("a fresh open skips the dedupe and opens a second tab on the same path", () => {
+		const layout = openAll(["/", "/backlog"]);
+		const onBridge = reduce(layout, {
+			kind: "focusTab",
+			tabId: layout.tabs[0]?.id ?? "",
+		});
+		const next = reduce(onBridge, { kind: "open", path: "/", fresh: true });
+		expect(tabPaths(next)).toEqual(["/", "/", "/backlog"]);
+		expect(next.activeTabId).toBe(next.tabs[1]?.id ?? "");
+	});
+
+	test("a fresh open at the tab cap is refused even when the path is open", () => {
+		const paths = Array.from({ length: MAX_TABS }, (_, i) => `/agent/a-${i}`);
+		const full = openAll(paths);
+		expect(
+			reduceLayout(full, { kind: "open", path: "/agent/a-0", fresh: true }),
+		).toEqual({ refused: "tab-cap" });
+	});
+
 	test("a new tab opens after the active one", () => {
 		const layout = openAll(["/", "/backlog"]);
 		const focused = reduce(layout, {

apps/ui/src/window-layout.ts

@@ -21,7 +21,7 @@ const STORAGE_KEY = "compass.windowLayout";
 const MAX_SEED = 1e9;
 
 export type LayoutAction =
-	| { kind: "open"; path: string; background?: boolean }
+	| { kind: "open"; path: string; background?: boolean; fresh?: boolean }
 	| { kind: "close"; tabId: string }
 	| { kind: "focusTab"; tabId: string }
 	| { kind: "move"; tabId: string; toIndex: number }
@@ -115,14 +115,18 @@ function withFocusedPath(tab: TabLayout, path: string): TabLayout {
 		: { ...tab, second: moved };
 }
 
+// `fresh` skips the dedupe: New tab always opens a tab, as in a browser.
 function open(
 	layout: WindowLayout,
 	path: string,
 	background: boolean,
+	fresh = false,
 ): WindowLayout | LayoutRefusal {
-	const existing = layout.tabs.find(
-		(tab) => tab.layout.kind === "single" && tab.layout.view.path === path,
-	);
+	const existing = fresh
+		? undefined
+		: layout.tabs.find(
+				(tab) => tab.layout.kind === "single" && tab.layout.view.path === path,
+			);
 	if (existing) {
 		return background || existing.id === layout.activeTabId
 			? layout
@@ -186,7 +190,12 @@ export function reduceLayout(
 ): WindowLayout | LayoutRefusal {
 	switch (action.kind) {
 		case "open":
-			return open(layout, action.path, action.background ?? false);
+			return open(
+				layout,
+				action.path,
+				action.background ?? false,
+				action.fresh,
+			);
 		case "close":
 			return close(layout, action.tabId);
 		case "focusTab":

docs/designs/DECISIONS.md

@@ -317,6 +317,7 @@ check enforces the mechanical half. Full rationale:
 | DL-389 | The one hash router stops choosing what `<main>` renders: it mirrors the focused view's path into the hash and applies hash changes to the focused view, while a `ViewHost` renders each view from the shared `appRoutes` table; browser history stays one linear stack whose entries carry the owning view id in history state, and a tab switch replaces the current entry rather than pushing | Active (Matt, 2026-10-04) | [in-window tabs §A2](ui/compass-in-window-tabs/design.md#a2--the-router-stays-the-url-bridge-not-the-pane-renderer) |
 | DL-390 | Window layout is a list of view tabs, each a single view or a bounded two-pane split; links navigate the focused view in place and `Mod`+click or middle-click opens a tab; an already-open path is deduped to its tab; at most 10 tabs; inactive tabs stay mounted and hidden; the layout persists per window in `sessionStorage`, and a deep-link hash wins over the restored layout | Active (Matt, 2026-10-04) | [in-window tabs §A3](ui/compass-in-window-tabs/design.md#a3--window-layout-tabs-each-a-single-view-or-a-two-pane-split) |
 | DL-391 | Tab and split commands bind to a second leader, `W`, under the leader-chord rules (not `Mod+T`/`W`/`Tab`, which the browser host cannot intercept), and each is also a palette command | Active (Matt, 2026-10-04) | [in-window tabs §A6](ui/compass-in-window-tabs/design.md#a6--keyboard) |
+| DL-409 | New tab (`W N`, palette "New tab") always opens a new tab on `/`, skipping the open-path dedupe, so it never just focuses an open Bridge tab; duplicate Bridge tabs are allowed and the 10-tab cap still applies. Amends DL-390's "an already-open path is deduped to its tab" clause for this command only | Active (Matt, 2026-10-06) | [in-window tabs §A6](ui/compass-in-window-tabs/design.md#a6--keyboard) |
 
 ## Threading & rendering