fix(dashboard): lazy-init useMobileKeyboard so remount has no stale render

When ChatView remounted (e.g. tab switch with keyboard still up), the
hook started with keyboardOpen=false and corrected itself only after
the effect ran. That single stale-state render briefly unhid the
executor status bar, which appeared as a blank pane covering half the
input box before the next state update settled it.

useState initializers now call getKeyboardMetrics() lazily on first
render so the very first paint already reflects the live keyboard
state.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/engine/src/__tests__/pi-create-fn-agent.test.ts

@@ -993,6 +993,36 @@ describe("createFnAgent", () => {
     }));
   });
 
+  it("continues session creation when setting thinking level hits reasoning conflict", async () => {
+    const { piLog } = await import("../logger.js");
+    const warnSpy = vi.spyOn(piLog, "warn").mockImplementation(() => {});
+    const setThinkingLevel = vi.fn(() => {
+      throw new Error("400 cannot specify both 'thinking' and 'reasoning_effort'");
+    });
+
+    createAgentSessionMock.mockResolvedValueOnce({
+      session: {
+        prompt: vi.fn(),
+        subscribe: vi.fn(),
+        dispose: vi.fn(),
+        setThinkingLevel,
+      },
+    });
+
+    const { createFnAgent } = await import("../pi.js");
+
+    await expect(createFnAgent({
+      cwd: "/tmp",
+      systemPrompt: "test",
+      tools: "readonly",
+      defaultThinkingLevel: "high",
+    })).resolves.toBeTruthy();
+
+    expect(setThinkingLevel).toHaveBeenCalledWith("high");
+    expect(warnSpy).toHaveBeenCalledWith(expect.stringContaining("Disabling explicit thinking level"));
+    warnSpy.mockRestore();
+  });
+
   describe("skill selection", () => {
     beforeEach(() => {
       // Reset modules to ensure fresh imports for each test