fix(app): show New workspace action on non-git sidebar projects (#1857)

* fix(app): show New workspace action on non-git sidebar projects

The per-project "New workspace" affordance in the sidebar (the project-
header + button and the empty-project ghost row) was gated on
host.canCreateWorktree, i.e. projectKind === "git". Non-git projects
(non_git / directory) therefore showed no way to add a workspace, even
though a host with the workspaceMultiplicity capability can create
additional local workspaces for them.

Thread the per-host workspaceMultiplicity flag into the sidebar project
row model and show the affordance when canCreateWorktree ||
supportsWorkspaceMultiplicity, matching the gate already used by the
global "New workspace" button and the Cmd+N handler. Rename the internal
trailing-action kind new_worktree -> new_workspace (a client-only UI
model, not a wire type) to reflect that it now also covers non-git
workspaces.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* test(app): expect the per-row New workspace icon on non-git projects

The sidebar "+" now shows for non-git projects on a multiplicity-capable
host, so the Model B sidebar spec no longer asserts the non-git project
has zero new-worktree icons — it now expects the icon, like git projects.
Also refresh the now-stale "no new-worktree icon" comments in the
entry-points spec (the picker is still one valid entry point).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

packages/app/src/components/sidebar-workspace-list.tsx

@@ -56,6 +56,7 @@ import { NestableScrollContainer } from "react-native-draggable-flatlist";
 import { DraggableList, type DraggableRenderItemInfo } from "./draggable-list";
 import type { DraggableListDragHandleProps } from "./draggable-list.types";
 import { getHostRuntimeStore, useHosts } from "@/runtime/host-runtime";
+import { useHostFeatureMap } from "@/runtime/host-features";
 import { useIsCompactFormFactor } from "@/constants/layout";
 import { useProjectIconDataByProjectKey } from "@/projects/project-icons";
 import {
@@ -1881,6 +1882,7 @@ function ProjectBlock({
   activeWorkspaceSelection,
   hostLabelByServerId,
   showHostLabels,
+  supportsMultiplicityByServerId,
 }: {
   project: SidebarProjectEntry;
   collapsed: boolean;
@@ -1902,14 +1904,16 @@ function ProjectBlock({
   activeWorkspaceSelection: ActiveWorkspaceSelection | null;
   hostLabelByServerId: ReadonlyMap<string, string>;
   showHostLabels: boolean;
+  supportsMultiplicityByServerId: ReadonlyMap<string, boolean>;
 }) {
   const rowModel = useMemo(
     () =>
       buildSidebarProjectRowModel({
         project,
         collapsed,
+        supportsMultiplicityByServerId,
       }),
-    [collapsed, project],
+    [collapsed, project, supportsMultiplicityByServerId],
   );
 
   const active = isProjectSelectedByRoute({
@@ -2062,7 +2066,7 @@ function ProjectBlock({
           containerStyle={styles.workspaceListContainer}
         />
       );
-    } else if (rowModel.trailingAction.kind === "new_worktree") {
+    } else if (rowModel.trailingAction.kind === "new_workspace") {
       projectChildren = (
         <NewWorkspaceGhostRow
           project={project}
@@ -2085,7 +2089,7 @@ function ProjectBlock({
         chevron={rowModel.chevron}
         onPress={handleToggleCollapsed}
         worktreeTarget={
-          rowModel.trailingAction.kind === "new_worktree" ? rowModel.trailingAction.target : null
+          rowModel.trailingAction.kind === "new_workspace" ? rowModel.trailingAction.target : null
         }
         isProjectActive={active}
         onWorkspacePress={onWorkspacePress}
@@ -2106,6 +2110,7 @@ function ProjectBlock({
 
 type ProjectBlockProps = Parameters<typeof ProjectBlock>[0];
 
+// oxlint-disable-next-line complexity
 function areProjectBlockPropsEqual(previous: ProjectBlockProps, next: ProjectBlockProps): boolean {
   return (
     previous.project === next.project &&
@@ -2117,6 +2122,7 @@ function areProjectBlockPropsEqual(previous: ProjectBlockProps, next: ProjectBlo
     previous.shortcutIndexByWorkspaceKey === next.shortcutIndexByWorkspaceKey &&
     previous.hostLabelByServerId === next.hostLabelByServerId &&
     previous.showHostLabels === next.showHostLabels &&
+    previous.supportsMultiplicityByServerId === next.supportsMultiplicityByServerId &&
     previous.parentGestureRef === next.parentGestureRef &&
     previous.onToggleCollapsed === next.onToggleCollapsed &&
     previous.onWorkspacePress === next.onWorkspacePress &&
@@ -2183,6 +2189,8 @@ export function SidebarWorkspaceList({
     }
     return labels;
   }, [hosts]);
+  const serverIds = useMemo(() => hosts.map((host) => host.serverId), [hosts]);
+  const supportsMultiplicityByServerId = useHostFeatureMap(serverIds, "workspaceMultiplicity");
   const showHostLabels = useMemo(() => shouldShowSidebarHostLabels(projects), [projects]);
 
   const content =
@@ -2208,6 +2216,7 @@ export function SidebarWorkspaceList({
         pathname={pathname}
         hostLabelByServerId={hostLabelByServerId}
         showHostLabels={showHostLabels}
+        supportsMultiplicityByServerId={supportsMultiplicityByServerId}
       />
     );
 
@@ -2256,6 +2265,7 @@ function ProjectModeList({
   pathname,
   hostLabelByServerId,
   showHostLabels,
+  supportsMultiplicityByServerId,
 }: Omit<
   SidebarWorkspaceListProps,
   "statusWorkspacePlacements" | "projectNamesByKey" | "groupMode" | "isRefreshing" | "onRefresh"
@@ -2263,6 +2273,7 @@ function ProjectModeList({
   pathname: string;
   hostLabelByServerId: ReadonlyMap<string, string>;
   showHostLabels: boolean;
+  supportsMultiplicityByServerId: ReadonlyMap<string, boolean>;
 }) {
   const { t } = useTranslation();
   const [creatingWorkspaceIds, setCreatingWorkspaceIds] = useState<Set<string>>(() => new Set());
@@ -2451,6 +2462,7 @@ function ProjectModeList({
           activeWorkspaceSelection={activeWorkspaceSelection}
           hostLabelByServerId={hostLabelByServerId}
           showHostLabels={showHostLabels}
+          supportsMultiplicityByServerId={supportsMultiplicityByServerId}
         />
       );
     },
@@ -2461,6 +2473,7 @@ function ProjectModeList({
       handleWorkspaceReorder,
       hostLabelByServerId,
       showHostLabels,
+      supportsMultiplicityByServerId,
       onWorkspacePress,
       onToggleProjectCollapsed,
       parentGestureRef,