fix(FN-678): preserve settings section state across reopen

- Add a shared settings section scope helper so the modal consistently resolves the active section
- Prevent the authentication auto-open flow from leaking into later general settings sessions
- Add regression coverage for reopening the settings modal after authentication and general entry points

packages/dashboard/app/components/SettingsModal.tsx

@@ -49,6 +49,11 @@ const SETTINGS_SECTIONS = [
 ] as const;
 
 export type SectionId = (typeof SETTINGS_SECTIONS)[number]["id"];
+type SectionScope = (typeof SETTINGS_SECTIONS)[number]["scope"];
+
+function getSectionScope(sectionId: SectionId): SectionScope {
+  return SETTINGS_SECTIONS.find((section) => section.id === sectionId)?.scope;
+}
 
 interface SettingsModalProps {
   onClose: () => void;
@@ -80,7 +85,7 @@ export function SettingsModal({
   const [prefixError, setPrefixError] = useState<string | null>(null);
 
   /** Get the scope of the currently active section */
-  const activeSectionScope = SETTINGS_SECTIONS.find((s) => s.id === activeSection)?.scope;
+  const activeSectionScope = getSectionScope(activeSection);
 
   // Auth state (independent of the settings save flow)
   const [authProviders, setAuthProviders] = useState<AuthProvider[]>([]);

packages/dashboard/app/components/__tests__/App.test.tsx

@@ -248,6 +248,9 @@ describe("App auto-open Settings on unauthenticated", () => {
       expect(screen.getByText("Anthropic")).toBeTruthy();
     });
 
+    // Authentication auto-open should not render General fields yet
+    expect(screen.queryByLabelText("Task Prefix")).toBeNull();
+
     // Close the auto-opened settings modal via Cancel button
     fireEvent.click(screen.getByText("Cancel"));
 

packages/dashboard/app/components/__tests__/SettingsModal.test.tsx

@@ -778,7 +778,26 @@ describe("SettingsModal", () => {
     // General content should be visible
     expect(screen.getByLabelText("Task Prefix")).toBeTruthy();
     // Authentication content should NOT be visible
-    expect(screen.queryByText("✗ Not authenticated")).toBeNull();
+    expect(screen.queryByText("Anthropic")).toBeNull();
+  });
+
+  it("preserves section-scope behavior across authentication auto-open and general reopen states", async () => {
+    const { unmount } = render(
+      <SettingsModal onClose={onClose} addToast={addToast} initialSection="authentication" />,
+    );
+    await waitFor(() => expect(fetchSettings).toHaveBeenCalled());
+    await waitFor(() => expect(fetchAuthStatus).toHaveBeenCalled());
+
+    expect(screen.getByText("Anthropic")).toBeTruthy();
+    expect(screen.queryByLabelText("Task Prefix")).toBeNull();
+
+    unmount();
+
+    render(<SettingsModal onClose={onClose} addToast={addToast} />);
+    await waitFor(() => expect(fetchSettings).toHaveBeenCalledTimes(2));
+
+    expect(screen.getByLabelText("Task Prefix")).toBeTruthy();
+    expect(screen.queryByText("Anthropic")).toBeNull();
   });
 
   it("shows sign-in hint when no providers are authenticated", async () => {