feat(chat): terminal chat parity for every tool; Desktop-like artifacts

- The chat over a terminal pane now covers Claude, Codex, omp, Cursor and
  Antigravity: Cursor's agent transcript and agy's step log
  (brain/<id>/.system_generated/logs/transcript_full.jsonl) are read as
  conversations; Cursor sessions are claimed by their workspace
- Replies appear as soon as they are written: the projects-tree watcher
  broadcasts `transcript_changed` (at most every 250 ms per session) and the
  chat re-reads the transcript while the terminal underneath draws
- Stop shows from the pane's own busy line (Claude/Codex `esc to interrupt`,
  agy `… esc to cancel`), or fresh output for omp/Cursor — no hooks needed
- Permission prompts read off the terminal become a card with the tool, its
  command and "Deny with a note"; Codex gets Permission mode / Model buttons
  that open its own numbered pickers, answered from the menu card
- Artifacts: cards for pages/documents/diagrams/tables/React components, a
  Preview | Code panel with versions, copy, download, save to the Artifacts
  Hub, full screen; sandboxed iframes without allow-same-origin
- Claude panes get CLAUDE_CODE_ENABLE_TODO_TOOLS=1 so the Progress panel has a
  plan; multi-question pane menus read their Next row and question tabs
- The realtime chat bridge (structured stdio, /api/chat-bridge, /ws-chat)
  from the unreleased ad9d475 is not kept

client/src/components/run/__tests__/ChatFilePreview.test.tsx

@@ -31,6 +31,10 @@ vi.mock("../../../lib/api", async (importOriginal) => {
         }),
         gitRawUrl: () => "",
       },
+      artifacts: {
+        pinFile: vi.fn().mockResolvedValue({ item: { id: 1 } }),
+        uploadFile: vi.fn().mockResolvedValue({ item: { id: 2 } }),
+      },
       sessions: {
         readImageUrl: (id: string, p: string) => `/img/${id}?path=${p}`,
         readFile: vi.fn((_id: string, p: string) =>
@@ -75,7 +79,11 @@ const scope = { laneId: 4, laneCwd: "/w", cwd: "/w", sessionId: "s1" };
 describe("FilePreview", () => {
   it("reads a workspace file through the lane", async () => {
     render(<FilePreview path="/w/src/a.ts" scope={scope} onClose={() => {}} />);
-    expect(await screen.findByText("export const a = 1;")).toBeTruthy();
+    expect(
+      await screen.findByText(
+        (_t, el) => el?.tagName === "CODE" && !!el.textContent?.includes("export const a = 1;")
+      )
+    ).toBeTruthy();
     expect(vi.mocked(api.lanes.gitFile)).toHaveBeenCalledWith(4, "src/a.ts");
   });
 
@@ -89,7 +97,11 @@ describe("FilePreview", () => {
   it("reads Windows paths the same way", async () => {
     const win = { laneId: 4, laneCwd: "D:\\w", cwd: "D:\\w", sessionId: "s1" };
     render(<FilePreview path={"D:\\w\\src\\a.ts"} scope={win} onClose={() => {}} />);
-    expect(await screen.findByText("export const a = 1;")).toBeTruthy();
+    expect(
+      await screen.findByText(
+        (_t, el) => el?.tagName === "CODE" && !!el.textContent?.includes("export const a = 1;")
+      )
+    ).toBeTruthy();
     expect(vi.mocked(api.lanes.gitFile)).toHaveBeenCalledWith(4, "src/a.ts");
     cleanup();
     const tool = "C:\\Users\\k\\.claude\\projects\\D--w\\s1\\tool-results\\b.txt";
@@ -144,7 +156,11 @@ describe("FileListModal", () => {
     );
     expect(screen.getByText("No preview for this file here")).toBeTruthy();
     fireEvent.click(screen.getByRole("button", { name: "a.ts" }));
-    expect(await screen.findByText("export const a = 1;")).toBeTruthy();
+    expect(
+      await screen.findByText(
+        (_t, el) => el?.tagName === "CODE" && !!el.textContent?.includes("export const a = 1;")
+      )
+    ).toBeTruthy();
   });
 });
 
@@ -172,3 +188,77 @@ describe("SkillListModal", () => {
     expect(screen.getByText("No preview for this file here")).toBeTruthy();
   });
 });
+
+describe("the artifact view", () => {
+  const html = (lines: string[]) =>
+    vi.mocked(api.lanes.gitFile).mockResolvedValueOnce({
+      available: true,
+      path: "page.html",
+      rev: "work",
+      binary: false,
+      truncated: false,
+      lines,
+    } as never);
+
+  it("runs a page in a sandbox with scripts but no same origin, and shows its code", async () => {
+    html(["<button>go</button>"]);
+    render(<FilePreview path="/w/page.html" scope={scope} onClose={() => {}} />);
+    const frame = (await screen.findByTestId("artifact-frame")) as HTMLIFrameElement;
+    expect(frame.getAttribute("sandbox")).toContain("allow-scripts");
+    expect(frame.getAttribute("sandbox")).not.toContain("allow-same-origin");
+    expect(frame.getAttribute("srcdoc")).toContain("<button>go</button>");
+    fireEvent.click(screen.getByTestId("artifact-tab-code"));
+    expect(screen.queryByTestId("artifact-frame")).toBeNull();
+    expect(
+      await screen.findByText(
+        (_t, el) => el?.tagName === "CODE" && !!el.textContent?.includes("<button>go</button>")
+      )
+    ).toBeTruthy();
+    cleanup();
+  });
+
+  it("steps back to an older version the conversation wrote", async () => {
+    html(["<p>two</p>"]);
+    const tool = (id: string, input: Record<string, unknown>, name = "Write") => ({
+      type: "assistant" as const,
+      timestamp: null,
+      content: [{ type: "tool_use" as const, id, name, input }],
+    });
+    const messages = [
+      tool("1", { file_path: "/w/page.html", content: "<p>one</p>" }),
+      tool("2", { file_path: "/w/page.html", old_string: "one", new_string: "two" }, "Edit"),
+    ];
+    render(
+      <FilePreview
+        path="/w/page.html"
+        scope={scope}
+        onClose={() => {}}
+        messages={messages as never}
+      />
+    );
+    const versions = await screen.findByTestId("artifact-versions");
+    expect(versions.textContent).toContain("2");
+    expect(
+      ((await screen.findByTestId("artifact-frame")) as HTMLIFrameElement).getAttribute("srcdoc")
+    ).toContain("two");
+    fireEvent.click(versions.querySelector("button")!);
+    expect(screen.getByTestId("artifact-frame").getAttribute("srcdoc")).toContain("<p>one</p>");
+    cleanup();
+  });
+
+  it("saves a workspace file to the Artifacts library by its path", async () => {
+    html(["<p>x</p>"]);
+    render(<FilePreview path="/w/page.html" scope={scope} onClose={() => {}} />);
+    await screen.findByTestId("artifact-frame");
+    fireEvent.click(screen.getByTestId("artifact-share"));
+    await vi.waitFor(() =>
+      expect(api.artifacts.pinFile).toHaveBeenCalledWith({
+        laneId: 4,
+        path: "page.html",
+        title: "page.html",
+        sessionId: "s1",
+      })
+    );
+    cleanup();
+  });
+});