FN-8556: fix Windows agent target selection

Make direct-chat Agent selection reliable when Windows Electron suppresses the click after pointer activation.

- Switch target mode on primary pointerdown while retaining keyboard activation.
- Expose selected Model and Agent modes with aria-pressed semantics.
- Cover pointer activation and persistence across direct-chat layouts.
- Add a patch changeset for the Windows selection fix.

Files changed:
 .changeset/fn-8556-windows-agent-selection.md      |  7 ++++
 .../app/components/ChatThinkingLevelControl.tsx    | 28 ++++++++++++-
 .../__tests__/ChatThinkingLevelControl.test.tsx    | 27 +++++++++++--
 .../__tests__/ChatView.thinking-level.test.tsx     | 46 +++++++++++++++++-----
 4 files changed, 93 insertions(+), 15 deletions(-)

Fusion-Task-Id: FN-8556

Fusion-Task-Lineage: 25b06177-3b59-4d2d-8440-e92fe7172259

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

.changeset/fn-8556-windows-agent-selection.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Make Windows direct-chat Agent selection switch visibly and reliably.
+category: fix
+dev: Handles primary pointer activation before an Electron host can suppress its following click.

packages/dashboard/app/components/ChatThinkingLevelControl.tsx

@@ -139,6 +139,18 @@ export function ChatThinkingLevelControl({
     void onChangeModel?.({ agentId: nextAgentId });
   };
 
+  /*
+  FNXC:Chat-ModelSwitch 2026-07-24-00:00:
+  Windows Electron can show the Agent toggle's pressed feedback after primary pointerdown while
+  its host prevents the following click. Commit the visual mode switch on primary pointerdown so
+  the available-agent list deterministically replaces the model picker; preserve click handling
+  only for keyboard/synthetic activation (`detail === 0`) so one pointer gesture does not reset
+  the local mode twice. `aria-pressed` makes the selected target observable to assistive tech.
+  */
+  const activateTargetMode = (mode: TargetMode) => {
+    setTargetMode(mode);
+  };
+
   const handleTriggerKeyDown = (event: KeyboardEvent<HTMLButtonElement>) => {
     if (event.key === "Escape") {
       setOpen(false);
@@ -197,7 +209,13 @@ export function ChatThinkingLevelControl({
                 type="button"
                 className={`chat-thinking-mode-btn${targetMode === "model" ? " chat-thinking-mode-btn--active" : ""}`}
                 data-testid="chat-thinking-mode-model"
-                onClick={() => setTargetMode("model")}
+                aria-pressed={targetMode === "model"}
+                onPointerDown={(event) => {
+                  if (event.button === 0) activateTargetMode("model");
+                }}
+                onClick={(event) => {
+                  if (event.detail === 0) activateTargetMode("model");
+                }}
               >
                 {t("chat.newChatModeModel", "Model")}
               </button>
@@ -205,7 +223,13 @@ export function ChatThinkingLevelControl({
                 type="button"
                 className={`chat-thinking-mode-btn${targetMode === "agent" ? " chat-thinking-mode-btn--active" : ""}`}
                 data-testid="chat-thinking-mode-agent"
-                onClick={() => setTargetMode("agent")}
+                aria-pressed={targetMode === "agent"}
+                onPointerDown={(event) => {
+                  if (event.button === 0) activateTargetMode("agent");
+                }}
+                onClick={(event) => {
+                  if (event.detail === 0) activateTargetMode("agent");
+                }}
               >
                 {t("chat.newChatModeAgent", "Agent")}
               </button>

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

@@ -126,15 +126,36 @@ describe("ChatThinkingLevelControl", () => {
     expect(screen.queryByRole("listbox")).toBeNull();
   });
 
-  it("the Model|Agent toggle swaps controls", () => {
+  it("switches to Agent mode during the Windows pointer activation sequence and exposes selected semantics", () => {
     render(<ChatThinkingLevelControl level={null} onChange={vi.fn()} models={models} agents={agents} />);
 
     fireEvent.click(screen.getByTestId("chat-thinking-btn"));
+    const modelMode = screen.getByTestId("chat-thinking-mode-model");
+    const agentMode = screen.getByTestId("chat-thinking-mode-agent");
     expect(screen.getByTestId("mock-model-dropdown")).toBeDefined();
+    expect(modelMode).toHaveAttribute("aria-pressed", "true");
+    expect(agentMode).toHaveAttribute("aria-pressed", "false");
 
-    fireEvent.click(screen.getByTestId("chat-thinking-mode-agent"));
+    // Electron on Windows visibly dispatches pointerdown before it completes click activation.
+    // Agent mode must render from that primary-pointer boundary, not wait for a click that a
+    // host surface can suppress after showing the pressed state.
+    fireEvent.pointerDown(agentMode, { button: 0, pointerType: "mouse" });
+    expect(agentMode).toHaveClass("chat-thinking-mode-btn--active");
+    expect(agentMode).toHaveAttribute("aria-pressed", "true");
+    expect(modelMode).toHaveAttribute("aria-pressed", "false");
+    expect(screen.queryByTestId("chat-thinking-model-picker")).toBeNull();
     expect(screen.getByTestId("chat-thinking-agent-list")).toBeDefined();
     expect(screen.getByTestId("chat-thinking-agent-agent-001")).toBeDefined();
+
+    fireEvent.pointerUp(agentMode, { button: 0, pointerType: "mouse" });
+    fireEvent.click(agentMode, { detail: 1 });
+    expect(screen.getByTestId("chat-thinking-agent-list")).toBeDefined();
+
+    // Keyboard button activation remains a click with no pointer detail.
+    fireEvent.click(modelMode, { detail: 0 });
+    expect(modelMode).toHaveClass("chat-thinking-mode-btn--active");
+    expect(modelMode).toHaveAttribute("aria-pressed", "true");
+    expect(screen.getByTestId("chat-thinking-model-picker")).toBeDefined();
   });
 
   it("selecting a model calls onChangeModel with the provider/model pair and closes", () => {

packages/dashboard/app/components/__tests__/ChatView.thinking-level.test.tsx

@@ -242,7 +242,12 @@ describe("ChatView thinking-level control (FN-7898)", () => {
     await renderWithAct(<ChatView projectId="proj-123" addToast={vi.fn()} />);
 
     fireEvent.click(screen.getByTestId("chat-thinking-btn"));
-    fireEvent.click(screen.getByTestId("chat-thinking-mode-agent"));
+    const agentMode = screen.getByTestId("chat-thinking-mode-agent");
+    fireEvent.pointerDown(agentMode, { button: 0, pointerType: "mouse" });
+    fireEvent.pointerUp(agentMode, { button: 0, pointerType: "mouse" });
+    fireEvent.click(agentMode, { detail: 1 });
+    expect(agentMode).toHaveAttribute("aria-pressed", "true");
+    expect(screen.queryByTestId("chat-thinking-model-picker")).toBeNull();
     fireEvent.click(screen.getByTestId("chat-thinking-agent-agent-002"));
 
     expect(setSessionModel).toHaveBeenCalledWith("sess-agent", { agentId: "agent-002" });
@@ -313,19 +318,40 @@ describe("ChatView thinking-level control (FN-7898)", () => {
     expect(screen.getByTestId("chat-thinking-agent-agent-001").className).toContain("chat-thinking-agent-item--selected");
   });
 
-  it("(f) renders the trigger without a layout/overflow regression at a mobile viewport", async () => {
+  it.each([
-    mockMobileViewport();
+    { name: "mobile", configure: mockMobileViewport, props: {} },
-    const session = makeSession({ id: "sess-mobile", cliExecutorAdapterId: null, thinkingLevel: null });
+    { name: "narrow floating", configure: mockDesktopViewport, props: { floating: true, compactLayout: true } },
-    mockUseChat.mockReturnValue(chatState({ activeSession: session, sessions: [session] }));
+  ])("(f) switches to and persists an Agent target from the $name direct-chat host", async ({ name, configure, props }) => {
+    configure();
+    const setSessionModel = vi.fn();
+    const session = makeSession({ id: `sess-${name.replaceAll(" ", "-")}`, cliExecutorAdapterId: null, agentId: useChatModule.FN_AGENT_ID });
+    const agentsMap = new Map([
+      ["agent-001", { id: "agent-001", name: "Alpha", role: "executor" }],
+      ["agent-002", { id: "agent-002", name: "Beta", role: "reviewer" }],
+    ] as const);
+    mockUseChat.mockReturnValue(chatState({ activeSession: session, sessions: [session], agentsMap, setSessionModel }));
 
-    await renderWithAct(<ChatView projectId="proj-123" addToast={vi.fn()} />);
+    await renderWithAct(<ChatView projectId="proj-123" addToast={vi.fn()} {...props} />);
+
+    expect(document.querySelector(".chat-view--narrow")).toBeTruthy();
+    if (props.floating) expect(document.querySelector(".chat-view--floating")).toBeTruthy();
 
     const trigger = screen.getByTestId("chat-thinking-btn");
-    expect(trigger).toBeInTheDocument();
-    // Shell/structure assertion consistent with other ChatView mobile tests:
-    // the trigger sits alongside the attach button inside the same input row.
     expect(trigger.closest(".chat-input-row")).not.toBeNull();
-    expect(trigger.closest(".chat-thinking-level-root")).not.toBeNull();
+    fireEvent.click(trigger);
+
+    // Match the Windows Electron pointer activation whose click can be consumed by a host.
+    const agentMode = screen.getByTestId("chat-thinking-mode-agent");
+    fireEvent.pointerDown(agentMode, { button: 0, pointerType: "mouse" });
+    fireEvent.pointerUp(agentMode, { button: 0, pointerType: "mouse" });
+    fireEvent.click(agentMode, { detail: 1 });
+
+    expect(agentMode).toHaveAttribute("aria-pressed", "true");
+    expect(screen.queryByTestId("chat-thinking-model-picker")).toBeNull();
+    expect(screen.getByTestId("chat-thinking-agent-list")).toBeInTheDocument();
+    fireEvent.click(screen.getByTestId("chat-thinking-agent-agent-002"));
+
+    expect(setSessionModel).toHaveBeenCalledWith(session.id, { agentId: "agent-002" });
   });
 
   it("(g) uses the resolved Settings default for both the in-chat and New Chat thinking-level labels", async () => {