Remove errant vertical gray line on regular chat input box

packages/dashboard/app/components/ChatView.css

@@ -1417,6 +1417,8 @@
      vertical flex sizing so the inline autosize height from ChatView.tsx is
      honored instead of collapsing back toward the one-line minimum. */
   flex: 0 0 auto;
+  width: 100%;
+  box-sizing: border-box;
   resize: none;
   border: 1px solid var(--border);
   border-radius: 12px;

packages/dashboard/app/components/__tests__/ChatView.regular-composer-no-right-line.test.tsx

@@ -0,0 +1,106 @@
+import { readFileSync } from "node:fs";
+import { resolve } from "node:path";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { ChatView } from "../ChatView";
+import * as useChatModule from "../../hooks/useChat";
+import * as useChatRoomsModule from "../../hooks/useChatRooms";
+import type { UseChatReturn } from "../../hooks/useChat";
+import type { UseChatRoomsResult } from "../../hooks/useChatRooms";
+import { _resetInitialViewportHeight } from "../../hooks/useMobileKeyboard";
+
+Element.prototype.scrollIntoView = vi.fn();
+
+vi.mock("../../hooks/useChat");
+vi.mock("../../hooks/useChatRooms");
+vi.mock("../../hooks/useNavigationHistory", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("../../hooks/useNavigationHistory")>();
+  return {
+    ...actual,
+    useNavigationHistoryContext: () => ({ pushNav: vi.fn(), replaceCurrent: vi.fn() }),
+  };
+});
+vi.mock("../../api", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("../../api")>();
+  return {
+    ...actual,
+    fetchAgents: vi.fn().mockResolvedValue([]),
+    fetchDiscoveredSkills: vi.fn().mockResolvedValue([]),
+    fetchTasks: vi.fn().mockResolvedValue([]),
+    searchFiles: vi.fn().mockResolvedValue({ files: [] }),
+  };
+});
+
+const chatViewCss = readFileSync(resolve(__dirname, "../ChatView.css"), "utf8");
+const mockUseChat = vi.mocked(useChatModule.useChat);
+const mockUseChatRooms = vi.mocked(useChatRoomsModule.useChatRooms);
+
+const defaultChatState: UseChatReturn = {
+  sessions: [],
+  activeSession: null,
+  sessionsLoading: false,
+  messages: [],
+  messagesLoading: false,
+  isStreaming: false,
+  streamingText: "",
+  streamingThinking: "",
+  streamingToolCalls: [],
+  selectSession: vi.fn(),
+  createSession: vi.fn(),
+  archiveSession: vi.fn(),
+  deleteSession: vi.fn(),
+  sendMessage: vi.fn(),
+  stopStreaming: vi.fn(),
+  pendingMessage: "",
+  clearPendingMessage: vi.fn(),
+  loadMoreMessages: vi.fn(),
+  hasMoreMessages: false,
+  searchQuery: "",
+  setSearchQuery: vi.fn(),
+  filteredSessions: [],
+  refreshSessions: vi.fn(),
+  agentsMap: new Map(),
+};
+
+const defaultRoomsState: UseChatRoomsResult = {
+  rooms: [],
+  roomsLoading: false,
+  roomsError: null,
+  activeRoom: null,
+  activeRoomMembers: [],
+  messages: [],
+  messagesLoading: false,
+  selectRoom: vi.fn(),
+  createRoom: vi.fn(),
+  deleteRoom: vi.fn(),
+  sendRoomMessage: vi.fn().mockResolvedValue(undefined),
+  refreshRooms: vi.fn(),
+};
+
+describe("ChatView regular composer right-edge artifact regression", () => {
+  beforeEach(() => {
+    _resetInitialViewportHeight();
+    vi.clearAllMocks();
+    mockUseChat.mockReturnValue(defaultChatState);
+    mockUseChatRooms.mockReturnValue(defaultRoomsState);
+  });
+
+  it("keeps textarea sizing rules and wrapper border invariants that prevent a right-edge line", () => {
+    render(<ChatView projectId="proj-123" addToast={vi.fn()} />);
+
+    expect(screen.getByPlaceholderText("Type a message...")).toBeInTheDocument();
+
+    const textareaRule = chatViewCss.match(/\.chat-input-textarea\s*\{[^}]*\}/);
+    expect(textareaRule).not.toBeNull();
+    expect(textareaRule?.[0]).toContain("box-sizing: border-box");
+    expect(textareaRule?.[0]).toContain("width: 100%");
+
+    const wrapperRule = chatViewCss.match(/\.chat-input-wrapper\s*\{[^}]*\}/);
+    expect(wrapperRule).not.toBeNull();
+    expect(wrapperRule?.[0]).not.toMatch(/border(?:-right)?\s*:/);
+
+    const dragoverRule = chatViewCss.match(/\.chat-input-wrapper--dragover\s*\{[^}]*\}/);
+    expect(dragoverRule).not.toBeNull();
+    expect(dragoverRule?.[0]).toContain("border: 1px dashed var(--todo)");
+  });
+});