feat(FN-4011): align room input keyboard handlers

Completes Step 1 of mobile touch-focus parity by aligning room input keyboard handlers in ChatView, with a regression test covering mobile room and direct composer touch-focus behavior.

Fusion-Task-Id: FN-4011

packages/dashboard/app/components/AgentDetailView.tsx

@@ -1612,7 +1612,6 @@ function RunsTab({
     }
   }, [initialRunId, preferActiveRun, runs, isLoadingRuns, handleRunClick]);
 
-
   const handleStopRun = async () => {
     const shouldStop = await confirm({
       title: "Stop Active Run",
@@ -1633,7 +1632,6 @@ function RunsTab({
     }
   };
 
-
   if (isLoadingRuns && runs.length === 0) {
     return (
       <div className="runs-tab">

packages/dashboard/app/components/ChatView.tsx

@@ -2164,6 +2164,17 @@ export function ChatView({ projectId, addToast, experimentalFeatures }: ChatView
                     value={messageInput}
                     onChange={handleInputChange}
                     onKeyDown={handleInputKeyDown}
+                    onKeyUp={handleInputKeyUp}
+                    onClick={handleInputSelectionChange}
+                    onBlur={handleInputBlur}
+                    onFocus={handleInputFocus}
+                    onTouchStart={(event) => {
+                      if (typeof window === "undefined") return;
+                      if (window.innerWidth > 768) return;
+                      if (document.activeElement === event.currentTarget) return;
+                      event.preventDefault();
+                      event.currentTarget.focus({ preventScroll: true });
+                    }}
                     rows={1}
                     data-testid="chat-input"
                   />

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

@@ -283,6 +283,7 @@ describe("AgentDetailView", () => {
       createdAt: "2024-01-01T00:00:00.000Z",
       updatedAt: "2024-01-01T00:00:00.000Z",
     } as any);
+    mockStartAgentRun.mockResolvedValue({ id: "run-003" } as any);
     // Default: no budget limit configured
     mockFetchAgentBudgetStatus.mockResolvedValue({
       agentId: "agent-001",

packages/dashboard/app/components/__tests__/ChatView.rooms.test.tsx

@@ -1,5 +1,5 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";
-import { act, render, screen, waitFor, within } from "@testing-library/react";
+import { act, fireEvent, render, screen, waitFor, within } from "@testing-library/react";
 import { userEvent } from "@testing-library/user-event";
 import { ChatView } from "../ChatView";
 import * as useChatModule from "../../hooks/useChat";
@@ -231,6 +231,40 @@ describe("ChatView — rooms (FN-3805..FN-3811 contract)", () => {
     mediaSpy.mockRestore();
   });
 
+  it("keeps room composer touch-focus behavior in parity with direct chat on mobile", async () => {
+    const mediaSpy = mockMobileViewport();
+    setup(
+      {
+        activeSession,
+        messages: [{ id: "msg-1", sessionId: activeSession.id, role: "assistant", content: "Direct hello", createdAt: "2026-04-08T00:00:00.000Z" }],
+      },
+      {
+        activeRoom: roomA,
+        messages: [{ id: "rmsg-1", roomId: roomA.id, role: "assistant", content: "Room hello", createdAt: "2026-04-08T00:00:00.000Z", senderAgentId: "agent-1", mentions: [] }],
+      },
+    );
+
+    render(<ChatView projectId="proj-123" addToast={vi.fn()} experimentalFeatures={{ chatRooms: true }} />);
+
+    const roomInput = screen.getByTestId("chat-input") as HTMLTextAreaElement;
+    const roomFocusSpy = vi.spyOn(roomInput, "focus");
+    await act(async () => {
+      fireEvent.touchStart(roomInput);
+    });
+    expect(roomFocusSpy).toHaveBeenCalledWith({ preventScroll: true });
+
+    await userEvent.click(screen.getByTestId("chat-sidebar-scope-direct"));
+
+    const directInput = screen.getByTestId("chat-input") as HTMLTextAreaElement;
+    const directFocusSpy = vi.spyOn(directInput, "focus");
+    await act(async () => {
+      fireEvent.touchStart(directInput);
+    });
+    expect(directFocusSpy).toHaveBeenCalledWith({ preventScroll: true });
+
+    mediaSpy.mockRestore();
+  });
+
   it("applies keyboard-active thread layout in room mode on mobile and preserves direct-chat parity", async () => {
     const mediaSpy = mockMobileViewport();
     const { listeners, mockVV } = mockMobileVisualViewport({ innerHeight: 800, vvHeight: 800 });