feat: open compose editor in edit mode with one click (#1592)

* feat: open compose editor in edit mode with one click

Remove the desktop double edit gate so Anatomy "Edit compose" and empty-stack
create land in an immediately editable workspace. Close discards both compose
and env buffers; deferred loads keep startInComposeEdit through unsaved confirm.

* docs: align compose editor close behavior and Edit compose labels

Update stack-management and editor docs for one-click edit mode.

Close discards unsaved compose/env edits. Anatomy shortcuts use Edit compose.

* fix(e2e): update routing test to use anatomy-edit-compose-btn test id

The compose editor env tab routing test was written against the old
'edit' button name. The single-compose-edit-gate branch renamed that
button to 'Edit compose' with test id 'anatomy-edit-compose-btn'.
Update the selector to match.

frontend/src/components/EditorLayout/MobileStackDetail.tsx

@@ -64,7 +64,6 @@ export function MobileStackDetail(props: EditorViewProps) {
         serviceAction,
         setLogsMode,
         setActiveTab,
-        setEditingCompose,
         setGitSourceOpen,
         requestDeleteStack,
         requestTakeDownStack,
@@ -79,6 +78,7 @@ export function MobileStackDetail(props: EditorViewProps) {
         onDismissRecovery,
         panelStartedAt,
         stackMuteActions,
+        openComposeEditor,
     } = props;
 
     const [segment, setSegment] = useState<Segment>('logs');
@@ -240,7 +240,7 @@ export function MobileStackDetail(props: EditorViewProps) {
                                 envContent={envContent}
                                 selectedEnvFile={selectedEnvFile}
                                 gitSourcePending={Boolean(gitSourcePendingMap[stackName])}
-                                onEditCompose={() => { setActiveTab('compose'); setEditingCompose(true); }}
+                                onEditCompose={openComposeEditor}
                                 onOpenGitSource={() => setGitSourceOpen(true)}
                                 onApplyUpdate={() => { void updateStack(); }}
                                 applying={loadingAction === 'update'}