diff --git a/cobot/commands/delete.py b/cobot/commands/delete.py
index 2f99049..0041a6c 100644
--- a/cobot/commands/delete.py
+++ b/cobot/commands/delete.py
@@ -178,13 +178,15 @@ def _task_delete(screen: LogScreen, remove_ros: bool, remove_webots: bool) -> No
         screen.set_progress(88, "Removing project directory...")
         _remove_project_dir(screen.write)
 
-        screen.set_progress(100, "Done")
-        screen.write("\n[green]Project fully removed.[/green]")
-        screen.finish(True)
+        if not screen.is_stopped():
+            screen.set_progress(100, "Done")
+            screen.write("\n[green]Project fully removed.[/green]")
+            screen.finish(True)
 
     except Exception as exc:
-        screen.write(f"\n[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"\n[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # Multi-step confirmation wizard before anything is deleted.
diff --git a/cobot/commands/doc_setup.py b/cobot/commands/doc_setup.py
index ca650a7..c5afaa7 100644
--- a/cobot/commands/doc_setup.py
+++ b/cobot/commands/doc_setup.py
@@ -53,6 +53,7 @@ def _image_exists() -> bool:
 def _build_docs_image(
     write: Write,
     on_progress: Optional[Callable[[float], None]] = None,
+    register_proc: Optional[Callable] = None,
 ) -> bool:
     write("[cyan][*][/cyan] Building documentation image (runs once)...")
     # DOCKER_BUILDKIT=0 gives us "Step X/Y" lines that we can parse for progress.
@@ -62,6 +63,8 @@ def _build_docs_image(
         ["docker", "build", "-t", _IMAGE_NAME, str(_DOC_DIR)],
         stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True, env=env,
     )
+    if register_proc:
+        register_proc(proc)
     for line in proc.stdout:
         s = line.rstrip()
         if s:
@@ -72,6 +75,8 @@ def _build_docs_image(
                 step, total = int(m.group(1)), int(m.group(2))
                 on_progress(step / total * 100)
     proc.wait()
+    if proc.returncode in (-9, -15):
+        return False
     if proc.returncode == 0:
         write("[green][ok][/green] Documentation image ready")
         return True
@@ -86,25 +91,34 @@ def _task_up(screen: LogScreen, port: str) -> None:
         if _is_running():
             screen.write(f"[green]Docs already running at:[/green] http://localhost:{port}")
             screen.write("  Stop with: [bold]cobot doc-setup down[/bold]")
-            screen.finish(True)
+            if not screen.is_stopped():
+                screen.finish(True)
             return
 
         if not _DOC_DIR.exists():
             screen.write(f"[red]Doc directory not found:[/red] {_DOC_DIR}")
-            screen.finish(False)
+            if not screen.is_stopped():
+                screen.finish(False)
             return
 
         if not _image_exists():
             screen.set_progress(0, "Building documentation image...")
-            if not _build_docs_image(
+            ok = _build_docs_image(
                 screen.write,
                 on_progress=lambda p: screen.set_progress(p * 0.85, "Building documentation image..."),
-            ):
+                register_proc=screen.set_proc,
+            )
+            if screen.is_stopped():
+                return
+            if not ok:
                 screen.finish(False)
                 return
         else:
             screen.write("[dim]Documentation image already built, skipping.[/dim]")
 
+        if screen.is_stopped():
+            return
+
         screen.set_progress(88, "Starting MkDocs server...")
         screen.write("\n[cyan][*][/cyan] Starting MkDocs server...")
         result = _docker(
@@ -116,6 +130,8 @@ def _task_up(screen: LogScreen, port: str) -> None:
             _IMAGE_NAME, "serve", "--dev-addr=0.0.0.0:8000",
             capture=True,
         )
+        if screen.is_stopped():
+            return
         if result.returncode != 0:
             screen.write(f"[red]Failed to start container.[/red]\n{result.stderr}")
             screen.finish(False)
@@ -125,11 +141,13 @@ def _task_up(screen: LogScreen, port: str) -> None:
         screen.write(f"\n[green]Docs running at:[/green] http://localhost:{port}")
         screen.write("  Edit files in [bold]doc/lwc-doc/docs/[/bold] — reloads automatically.")
         screen.write("  Stop with: [bold]cobot doc-setup down[/bold]")
-        screen.finish(True)
+        if not screen.is_stopped():
+            screen.finish(True)
 
     except Exception as exc:
-        screen.write(f"[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # Stop the running docs container.
@@ -138,17 +156,21 @@ def _task_down(screen: LogScreen) -> None:
     try:
         if not _is_running():
             screen.write("[yellow]Docs container is not running.[/yellow]")
-            screen.finish(True)
+            if not screen.is_stopped():
+                screen.finish(True)
             return
         screen.set_progress(30, "Stopping container...")
         screen.write("[cyan][*][/cyan] Stopping documentation server...")
         _docker("stop", _CONTAINER_NAME)
+        if screen.is_stopped():
+            return
         screen.set_progress(100, "Done")
         screen.write("[green][ok][/green] Container stopped.")
         screen.finish(True)
     except Exception as exc:
-        screen.write(f"[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # Stop the container, remove the old image, rebuild it, and start a new container.
@@ -159,19 +181,27 @@ def _task_rebuild(screen: LogScreen, port: str) -> None:
             screen.set_progress(5, "Stopping container...")
             screen.write("[cyan][*][/cyan] Stopping existing container...")
             _docker("stop", _CONTAINER_NAME)
+            if screen.is_stopped():
+                return
             screen.write("[green][ok][/green] Stopped.")
 
         if _image_exists():
             screen.set_progress(15, "Removing old image...")
             screen.write("[cyan][*][/cyan] Removing old image...")
             _docker("rmi", "-f", _IMAGE_NAME)
+            if screen.is_stopped():
+                return
             screen.write("[green][ok][/green] Image removed.")
 
         screen.set_progress(20, "Building documentation image...")
-        if not _build_docs_image(
+        ok = _build_docs_image(
             screen.write,
             on_progress=lambda p: screen.set_progress(20 + p * 0.68, "Building documentation image..."),
-        ):
+            register_proc=screen.set_proc,
+        )
+        if screen.is_stopped():
+            return
+        if not ok:
             screen.finish(False)
             return
 
@@ -184,6 +214,8 @@ def _task_rebuild(screen: LogScreen, port: str) -> None:
             _IMAGE_NAME, "serve", "--dev-addr=0.0.0.0:8000",
             capture=True,
         )
+        if screen.is_stopped():
+            return
         if result.returncode != 0:
             screen.write(f"[red]Failed to start container.[/red]\n{result.stderr}")
             screen.finish(False)
@@ -192,11 +224,13 @@ def _task_rebuild(screen: LogScreen, port: str) -> None:
         screen.set_progress(100, "Server running")
         screen.write(f"\n[green]Docs running at:[/green] http://localhost:{port}")
         screen.write("  Stop with: [bold]cobot doc-setup down[/bold]")
-        screen.finish(True)
+        if not screen.is_stopped():
+            screen.finish(True)
 
     except Exception as exc:
-        screen.write(f"[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # One app handles all three actions (up/down/rebuild) by branching in on_mount.
diff --git a/cobot/commands/docker_setup.py b/cobot/commands/docker_setup.py
index d708f21..4d43c8b 100644
--- a/cobot/commands/docker_setup.py
+++ b/cobot/commands/docker_setup.py
@@ -68,6 +68,7 @@ def _build_image(
     on_progress: Optional[Callable[[float], None]] = None,
     parent_tag: Optional[str] = None,
     build_type: str = "release",
+    register_proc: Optional[Callable] = None,
 ) -> bool:
     write(f"[cyan][*][/cyan] Building [bold]{name}[/bold]...")
     # DOCKER_BUILDKIT=0 gives us "Step X/Y" lines in the output which we parse for progress.
@@ -84,6 +85,8 @@ def _build_image(
     proc = subprocess.Popen(
         cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True, env=env,
     )
+    if register_proc:
+        register_proc(proc)
     for line in proc.stdout:
         s = line.rstrip()
         if s:
@@ -94,6 +97,8 @@ def _build_image(
                 step, total = int(m.group(1)), int(m.group(2))
                 on_progress(step / total * 100)
     proc.wait()
+    if proc.returncode in (-9, -15):
+        return False
     if proc.returncode == 0:
         write(f"[green][ok][/green] {name}")
         return True
@@ -102,12 +107,13 @@ def _build_image(
 
 
 # Pull a Docker image from Hub and track progress by counting downloaded layers.
-# Скачиваем Docker-образ с Hub и отслеживаем прогресс по количеству скачанных слоёв.
+# Скачиваем Docker-образ с Hub и отслеживаем прогресс по количеством скачанных слоёв.
 def _pull_image(
     name: str,
     tag: str,
     write: Write,
     on_progress: Optional[Callable[[float], None]] = None,
+    register_proc: Optional[Callable] = None,
 ) -> bool:
     write(f"[cyan][*][/cyan] Pulling [bold]{name}[/bold]  ({tag})...")
     if on_progress:
@@ -117,6 +123,8 @@ def _pull_image(
         ["docker", "pull", tag],
         stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True,
     )
+    if register_proc:
+        register_proc(proc)
     layers_total = 0
     layers_done = 0
     for line in proc.stdout:
@@ -132,6 +140,8 @@ def _pull_image(
             if on_progress and layers_total > 0:
                 on_progress(5 + layers_done / layers_total * 90)
     proc.wait()
+    if proc.returncode in (-9, -15):
+        return False
     if proc.returncode == 0:
         write(f"[green][ok][/green] {name}")
         if on_progress:
@@ -156,6 +166,8 @@ def _task_execute(screen: LogScreen, cfg: _Config) -> None:
                 f"ROS {cfg.ros_version} — {cfg.build_type}[/bold]\n"
             )
             for i, name in enumerate(chain):
+                if screen.is_stopped():
+                    return
                 lo = i / n * 100
                 hi = (i + 1) / n * 100
                 screen.set_progress(lo, f"Image {i + 1}/{n}: building {name}...")
@@ -164,7 +176,8 @@ def _task_execute(screen: LogScreen, cfg: _Config) -> None:
                 dockerfile = _DOCKER_DIR / cfg.ros_version / name / "Dockerfile"
                 if not dockerfile.exists():
                     screen.write(f"[red]Dockerfile not found:[/red] {dockerfile}")
-                    screen.finish(False)
+                    if not screen.is_stopped():
+                        screen.finish(False)
                     return
                 ctx = _PROJECT_DIR if name in _NEEDS_PROJECT_CTX else dockerfile.parent
                 parent_name = _IMAGE_PARENT.get(name)
@@ -172,23 +185,28 @@ def _task_execute(screen: LogScreen, cfg: _Config) -> None:
                     f"{cfg.image_prefix}:{parent_name}-{cfg.ros_version}"
                     if parent_name else None
                 )
-                if not _build_image(
+                ok = _build_image(
                     name, tag, dockerfile, ctx, screen.write,
                     on_progress=lambda p, lo=lo, hi=hi: screen.set_progress(
                         lo + p * (hi - lo) / 100, f"Image {i + 1}/{n}: building {name}..."
                     ),
                     parent_tag=parent_tag,
                     build_type=cfg.build_type,
-                ):
+                    register_proc=screen.set_proc,
+                )
+                if screen.is_stopped():
+                    return
+                if not ok:
                     screen.finish(False)
                     return
                 screen.set_progress(hi)
 
-            screen.set_progress(100, "All images built")
-            screen.write(
-                f"\n[green]Done.[/green] "
-                f"Images tagged [bold]{cfg.image_prefix}:<name>-{cfg.ros_version}[/bold]."
-            )
+            if not screen.is_stopped():
+                screen.set_progress(100, "All images built")
+                screen.write(
+                    f"\n[green]Done.[/green] "
+                    f"Images tagged [bold]{cfg.image_prefix}:<name>-{cfg.ros_version}[/bold]."
+                )
 
         else:
             short = "webots" if cfg.variant == "webots" else "iiwa"
@@ -199,20 +217,26 @@ def _task_execute(screen: LogScreen, cfg: _Config) -> None:
                 f"ROS {cfg.ros_version} — {cfg.build_type}[/bold]\n"
             )
             screen.set_progress(0, f"Pulling {full_ref}...")
-            if not _pull_image(
+            ok = _pull_image(
                 short, full_ref, screen.write,
                 on_progress=lambda p: screen.set_progress(p, f"Pulling {full_ref}..."),
-            ):
+                register_proc=screen.set_proc,
+            )
+            if screen.is_stopped():
+                return
+            if not ok:
                 screen.finish(False)
                 return
             screen.set_progress(100, "Pull complete")
             screen.write(f"\n[green]Done.[/green] Image ready: [bold]{full_ref}[/bold].")
 
-        screen.finish(True)
+        if not screen.is_stopped():
+            screen.finish(True)
 
     except Exception as exc:
-        screen.write(f"\n[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"\n[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # Scan the docker/ directory for subdirectories named after ROS versions (e.g. jazzy).
diff --git a/cobot/commands/local_setup.py b/cobot/commands/local_setup.py
index e0ab50d..bebc5a9 100644
--- a/cobot/commands/local_setup.py
+++ b/cobot/commands/local_setup.py
@@ -78,7 +78,13 @@ def _run_quiet(cmd: List[str], write: Write | None = None, env: dict | None = No
 
 # Run a command and stream every output line to the log in real time.
 # Запускаем команду и транслируем каждую строку вывода в лог в реальном времени.
-def _run_logged(cmd: List[str], write: Write, env: dict | None = None, cwd=None) -> None:
+def _run_logged(
+    cmd: List[str],
+    write: Write,
+    env: dict | None = None,
+    cwd=None,
+    register_proc: Callable | None = None,
+) -> None:
     proc = subprocess.Popen(
         cmd,
         stdout=subprocess.PIPE,
@@ -87,12 +93,14 @@ def _run_logged(cmd: List[str], write: Write, env: dict | None = None, cwd=None)
         env=env or os.environ,
         cwd=cwd,
     )
+    if register_proc:
+        register_proc(proc)
     for line in proc.stdout:
         s = line.rstrip()
         if s:
             write(s)
     proc.wait()
-    if proc.returncode != 0:
+    if proc.returncode not in (0, -9):
         raise RuntimeError(f"Command failed: {cmd[0]}")
 
 
@@ -101,6 +109,7 @@ def _run_apt_with_progress(
     write: Write,
     on_progress: Callable[[float], None],
     env: dict | None = None,
+    register_proc: Callable | None = None,
 ) -> None:
     """Run an apt command and feed real percentage from APT::Status-Fd to on_progress(0-100)."""
     # APT::Status-Fd makes apt write progress lines to a pipe descriptor instead of stdout.
@@ -110,7 +119,7 @@ def _run_apt_with_progress(
     r_fd, w_fd = os.pipe()
     try:
         proc = subprocess.Popen(
-            cmd + [f"-o", f"APT::Status-Fd={w_fd}"],
+            cmd + ["-o", f"APT::Status-Fd={w_fd}"],
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             text=True,
@@ -122,6 +131,11 @@ def _run_apt_with_progress(
         # Закрываем пишущий конец в родительском процессе, чтобы читающий поток получил EOF при выходе apt.
         os.close(w_fd)
 
+    # Tell the caller about this process so it can be killed if the user cancels.
+    # Сообщаем вызывающему о процессе, чтобы его можно было завершить при отмене пользователем.
+    if register_proc:
+        register_proc(proc)
+
     def _read_status() -> None:
         with os.fdopen(r_fd, "r") as f:
             for line in f:
@@ -141,7 +155,7 @@ def _run_apt_with_progress(
             write(s)
     proc.wait()
     t.join()
-    if proc.returncode != 0:
+    if proc.returncode not in (0, -9):
         raise RuntimeError(f"Command failed: {cmd[0]}")
 
 
@@ -162,7 +176,11 @@ def _setup_locale(write: Write) -> None:
 
 # Add the official ROS2 apt repository and its signing key so we can install ROS2 packages.
 # Добавляем официальный apt-репозиторий ROS2 и его ключ подписи, чтобы можно было установить пакеты ROS2.
-def _add_ros2_repo(write: Write, on_progress: Optional[Callable[[float], None]] = None) -> None:
+def _add_ros2_repo(
+    write: Write,
+    on_progress: Optional[Callable[[float], None]] = None,
+    register_proc: Callable | None = None,
+) -> None:
     def _prog(p: float) -> None:
         if on_progress:
             on_progress(p)
@@ -171,7 +189,6 @@ def _add_ros2_repo(write: Write, on_progress: Optional[Callable[[float], None]]
 
     # Best-effort update - 60 second timeout so a bad mirror doesn't hang forever.
     # Фоновое обновление с таймаутом 60 секунд, чтобы зависший зеркальный сервер не блокировал процесс.
-    # subprocess.run(["sudo", "apt-get", "update", "-qq"] + _APT_TIMEOUTS, capture_output=True, timeout=120)
     subprocess.run(["sudo", "apt-get", "update"] + _APT_TIMEOUTS, capture_output=True, timeout=120)
     _prog(15)
 
@@ -224,6 +241,7 @@ def _add_ros2_repo(write: Write, on_progress: Optional[Callable[[float], None]]
         write,
         lambda p: _prog(70 + p * 0.30),
         _APT_ENV,
+        register_proc=register_proc,
     )
     write("[green][ok][/green] ROS2 repository ready")
     _prog(100)
@@ -231,13 +249,18 @@ def _add_ros2_repo(write: Write, on_progress: Optional[Callable[[float], None]]
 
 # Install the full ROS2 Jazzy Desktop and the developer tools (colcon, rosdep, etc.).
 # Устанавливаем полный ROS2 Jazzy Desktop и инструменты разработчика (colcon, rosdep и т.д.).
-def _install_ros2_jazzy(write: Write, on_progress: Optional[Callable[[float], None]] = None) -> None:
+def _install_ros2_jazzy(
+    write: Write,
+    on_progress: Optional[Callable[[float], None]] = None,
+    register_proc: Callable | None = None,
+) -> None:
     write("[cyan][*][/cyan] Installing ros-jazzy-desktop and ros-dev-tools...")
     _run_apt_with_progress(
         ["sudo", "apt-get", "install", "-y", "ros-jazzy-desktop", "ros-dev-tools"] + _APT_TIMEOUTS,
         write,
         on_progress or (lambda _: None),
         _APT_ENV,
+        register_proc=register_proc,
     )
     write("[green][ok][/green] ROS2 Jazzy Desktop installed")
 
@@ -288,16 +311,24 @@ def _task_install_jazzy(screen: LogScreen) -> None:
         _add_ros2_repo(
             screen.write,
             on_progress=lambda p: screen.set_progress(5 + p * 0.15),
+            register_proc=screen.set_proc,
         )
 
+        if screen.is_stopped():
+            return
+
         # Step 3 — ROS2 Jazzy  (20 → 85 %)
         screen.set_progress(20, "Installing ROS2 Jazzy Desktop...")
         screen.write("\n[bold]Step 3 / 5 — ROS2 Jazzy Desktop[/bold]")
         _install_ros2_jazzy(
             screen.write,
             on_progress=lambda p: screen.set_progress(20 + p * 0.65),
+            register_proc=screen.set_proc,
         )
 
+        if screen.is_stopped():
+            return
+
         # Step 4 — colcon  (85 → 92 %)
         screen.set_progress(85, "Installing colcon...")
         screen.write("\n[bold]Step 4 / 5 — colcon[/bold]")
@@ -309,13 +340,15 @@ def _task_install_jazzy(screen: LogScreen) -> None:
         _setup_shell_rc(screen.write)
         screen.set_progress(100, "Done")
 
-        screen.write(
-            "\nRestart the terminal, then run [bold]cobot local-setup[/bold] again to build."
-        )
-        screen.finish(True)
+        if not screen.is_stopped():
+            screen.write(
+                "\nRestart the terminal, then run [bold]cobot local-setup[/bold] again to build."
+            )
+            screen.finish(True)
     except Exception as exc:
-        screen.write(f"\n[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"\n[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # Build all project packages with colcon and track progress by counting finished packages.
@@ -348,14 +381,16 @@ def _task_build(screen: LogScreen) -> None:
                 built += 1
                 screen.set_progress(built / total * 100, f"{built} / {total} packages done")
 
-        _run_logged(["colcon", "build", "--symlink-install"], _track, cwd=_PROJECT_DIR)
+        _run_logged(["colcon", "build", "--symlink-install"], _track, cwd=_PROJECT_DIR, register_proc=screen.set_proc)
 
-        screen.set_progress(100, "Build complete")
-        screen.write("\nActivate workspace:  [bold]source install/setup.bash[/bold]")
-        screen.finish(True)
+        if not screen.is_stopped():
+            screen.set_progress(100, "Build complete")
+            screen.write("\nActivate workspace:  [bold]source install/setup.bash[/bold]")
+            screen.finish(True)
     except Exception as exc:
-        screen.write(f"\n[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"\n[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # Webots version that matches the Docker images used in this project.
@@ -386,16 +421,31 @@ def _task_install_webots(screen: LogScreen) -> None:
             screen.write(f"[dim]{_WEBOTS_DEB_URL}[/dim]\n")
             screen.set_progress(0, "Downloading Webots...")
 
-            # urllib calls this hook periodically with how many bytes have been downloaded.
-            # urllib вызывает этот обратный вызов периодически с количеством скачанных байт.
-            def _hook(blocks: int, block_size: int, total: int) -> None:
-                if total > 0:
-                    pct = min(blocks * block_size / total * 65, 65)
-                    mb = blocks * block_size / 1_048_576
-                    total_mb = total / 1_048_576
-                    screen.set_progress(pct, f"Downloading... {mb:.0f} / {total_mb:.0f} MB")
+            # Download in 64 KB chunks so we can update the progress bar and bail out if the user
+            # cancels midway through instead of blocking in urlretrieve until the full file arrives.
+            # Скачиваем по 64 КБ, чтобы обновлять прогресс-бар и прерваться при отмене пользователем,
+            # а не блокироваться в urlretrieve до получения всего файла.
+            with urllib.request.urlopen(_WEBOTS_DEB_URL, timeout=30) as resp:
+                total = int(resp.headers.get("Content-Length", 0))
+                downloaded = 0
+                with open(deb_path, "wb") as f:
+                    while True:
+                        if screen.is_stopped():
+                            return
+                        chunk = resp.read(65536)
+                        if not chunk:
+                            break
+                        f.write(chunk)
+                        downloaded += len(chunk)
+                        if total > 0:
+                            pct = min(downloaded / total * 65, 65)
+                            mb = downloaded / 1_048_576
+                            total_mb = total / 1_048_576
+                            screen.set_progress(pct, f"Downloading... {mb:.0f} / {total_mb:.0f} MB")
+
+            if screen.is_stopped():
+                return
 
-            urllib.request.urlretrieve(_WEBOTS_DEB_URL, deb_path, _hook)
             screen.write("[green]Download complete.[/green]")
             screen.set_progress(65, "Installing package...")
 
@@ -404,23 +454,28 @@ def _task_install_webots(screen: LogScreen) -> None:
                 stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
                 text=True,
             )
+            screen.set_proc(proc)
             for line in proc.stdout:
                 s = line.rstrip()
                 if s:
                     screen.write(s)
             proc.wait()
 
-        if proc.returncode != 0:
+        if proc.returncode not in (0, -9):
             screen.write("\n[red]Installation failed.[/red]")
             screen.finish(False)
             return
 
+        if screen.is_stopped():
+            return
+
         screen.set_progress(100, "Done")
         screen.write("\n[green]Webots installed successfully.[/green]")
         screen.finish(True)
     except Exception as exc:
-        screen.write(f"\n[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"\n[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 # Minimal single-question app used between steps where a full wizard is not needed.
diff --git a/cobot/commands/update.py b/cobot/commands/update.py
index 3505755..e99581e 100644
--- a/cobot/commands/update.py
+++ b/cobot/commands/update.py
@@ -32,6 +32,8 @@ def _task_update(screen: LogScreen) -> None:
             ["git", "fetch", "origin"],
             cwd=_PROJECT_DIR, capture_output=True, text=True,
         )
+        if screen.is_stopped():
+            return
         if fetch.returncode != 0:
             screen.write(f"[red]Fetch failed:[/red] {fetch.stderr.strip()}")
             screen.finish(False)
@@ -46,9 +48,10 @@ def _task_update(screen: LogScreen) -> None:
         ).strip()
 
         if behind == "0":
-            screen.set_progress(100, "Already up to date")
-            screen.write("[green][ok][/green] Already up to date.")
-            screen.finish(True)
+            if not screen.is_stopped():
+                screen.set_progress(100, "Already up to date")
+                screen.write("[green][ok][/green] Already up to date.")
+                screen.finish(True)
             return
 
         # Show which commits are coming in so the user knows what changed.
@@ -68,6 +71,8 @@ def _task_update(screen: LogScreen) -> None:
             ["git", "pull", "origin", branch],
             capture_output=True, text=True, cwd=_PROJECT_DIR,
         )
+        if screen.is_stopped():
+            return
         if pull.returncode != 0:
             for line in (pull.stdout + pull.stderr).splitlines():
                 if line.strip():
@@ -86,18 +91,22 @@ def _task_update(screen: LogScreen) -> None:
             ["uv", "tool", "install", "--editable", str(_PROJECT_DIR)],
             capture_output=True, text=True,
         )
+        if screen.is_stopped():
+            return
         if reinstall.returncode == 0:
             screen.write("[green][ok][/green] cobot reinstalled")
         else:
             screen.write(f"[yellow]Warning:[/yellow] reinstall failed — {reinstall.stderr.strip()}")
 
-        screen.set_progress(100, "Done")
-        screen.write("\n[green]Project updated successfully.[/green]")
-        screen.finish(True)
+        if not screen.is_stopped():
+            screen.set_progress(100, "Done")
+            screen.write("\n[green]Project updated successfully.[/green]")
+            screen.finish(True)
 
     except Exception as exc:
-        screen.write(f"\n[red]Error:[/red] {exc}")
-        screen.finish(False)
+        if not screen.is_stopped():
+            screen.write(f"\n[red]Error:[/red] {exc}")
+            screen.finish(False)
 
 
 class _UpdateApp(App[None]):
diff --git a/cobot/tui.py b/cobot/tui.py
index 1d62d1a..779a8e5 100644
--- a/cobot/tui.py
+++ b/cobot/tui.py
@@ -184,6 +184,10 @@ class LogScreen(Screen[bool]):
         self._finished = False
         self._success = False
         self._show_progress = show_progress
+        # Tracks the subprocess that is currently running so on_unmount can kill it.
+        # Отслеживает текущий subprocess, чтобы on_unmount мог его завершить.
+        self._active_proc = None
+        self._stopped = False
 
     def compose(self) -> ComposeResult:
         yield Static(self._title, id="step")
@@ -201,6 +205,29 @@ class LogScreen(Screen[bool]):
         # Запускаем задачу в отдельном потоке, чтобы интерфейс не зависал.
         self.app.run_worker(lambda: self._run_fn(self), thread=True)
 
+    def set_proc(self, proc) -> None:
+        # Register the subprocess that is currently running.
+        # Called from the worker thread - GIL makes simple assignment safe here.
+        # Регистрируем текущий subprocess.
+        # Вызывается из рабочего потока - простое присваивание безопасно благодаря GIL.
+        self._active_proc = proc
+
+    def is_stopped(self) -> bool:
+        # Return True if the user has closed the screen before the task finished.
+        # Возвращает True если пользователь закрыл экран до завершения задачи.
+        return self._stopped
+
+    def on_unmount(self) -> None:
+        # Kill the active subprocess when the screen closes so it does not keep running in the background.
+        # Убиваем активный subprocess при закрытии экрана, чтобы он не продолжал работать в фоне.
+        self._stopped = True
+        proc = self._active_proc
+        if proc is not None:
+            try:
+                proc.kill()
+            except Exception:
+                pass
+
     def set_progress(self, pct: float, label: str = "") -> None:
         # Thread-safe - this is called from the worker thread, not the UI thread.
         # Потокобезопасно - вызывается из рабочего потока, а не из потока интерфейса.