Filter DA1 responses from replay buffer on WebSocket connect

The replay buffer can contain DA1/DA2 terminal attribute responses
(e.g., \x1b[?1;10;0c) that were captured before filtering was added
to the session classes. These responses appear as visible text like
'1;10;0c' when sent to the client on reconnect.

This adds an additional filter pass when sending the replay buffer,
ensuring no DA1 responses reach the client regardless of when they
were captured.

tests/test_cli.py

@@ -40,6 +40,7 @@ class TestCLI:
 
     def test_cli_runs_default_shell(self, monkeypatch):
         import os
+
         calls: dict[str, object] = {}
 
         class FakeServer:

tests/test_cli_landing.py

@@ -7,7 +7,6 @@ from webterm import cli
 
 
 def test_cli_landing_manifest_runs(monkeypatch, tmp_path: Path):
-
     manifest = tmp_path / "landing.yaml"
     manifest.write_text(
         """
@@ -40,7 +39,6 @@ def test_cli_landing_manifest_runs(monkeypatch, tmp_path: Path):
 
 
 def test_cli_compose_manifest_runs(monkeypatch, tmp_path: Path):
-
     manifest = tmp_path / "compose.yaml"
     manifest.write_text(
         """

tests/test_docker_stats.py

@@ -172,10 +172,10 @@ class TestDockerStatsCollector:
         """Services can be added dynamically after start."""
         collector = DockerStatsCollector("/nonexistent")
         collector._service_names = ["svc1"]
-        
+
         collector.add_service("svc2")
         assert "svc2" in collector._service_names
-        
+
         # Adding same service again is a no-op
         collector.add_service("svc2")
         assert collector._service_names.count("svc2") == 1
@@ -183,17 +183,17 @@ class TestDockerStatsCollector:
     def test_remove_service_dynamic(self):
         """Services can be removed dynamically."""
         from collections import deque
-        
+
         collector = DockerStatsCollector("/nonexistent")
         collector._service_names = ["svc1", "svc2"]
         collector._cpu_history["svc1"] = deque([10.0, 20.0])
         collector._prev_cpu["svc1"] = (100, 200)
-        
+
         collector.remove_service("svc1")
         assert "svc1" not in collector._service_names
         assert "svc1" not in collector._cpu_history
         assert "svc1" not in collector._prev_cpu
-        
+
         # Removing non-existent service is safe
         collector.remove_service("nonexistent")  # Should not raise
 

tests/test_local_server_websocket_integration.py

@@ -16,6 +16,7 @@ from webterm.types import RouteKey, SessionID
 if TYPE_CHECKING:
     from collections.abc import AsyncIterator
 
+
 async def _make_client(server: LocalServer) -> TestClient:
     app = web.Application()
     app.add_routes(server._build_routes())

tests/test_session_manager.py

@@ -215,6 +215,7 @@ class TestSessionManager:
             assert result is not None
             assert isinstance(result, DockerExecSession)
 
+
 class TestSessionManagerRoutes:
     """Tests for SessionManager route handling."""
 

tests/test_terminal_session.py

@@ -168,17 +168,11 @@ class TestTerminalSession:
         session = TerminalSession(mock_poller, "test-session", command)
 
         with (
-            patch(
-                "webterm.terminal_session.pty.fork", return_value=(pty.CHILD, 123)
-            ) as mock_fork,
+            patch("webterm.terminal_session.pty.fork", return_value=(pty.CHILD, 123)) as mock_fork,
             patch("webterm.terminal_session.version", return_value="0.0.0"),
             patch("webterm.terminal_session.shlex.split", wraps=shlex.split) as mock_split,
-            patch(
-                "webterm.terminal_session.os.execvp", side_effect=OSError()
-            ) as mock_execvp,
-            patch(
-                "webterm.terminal_session.os._exit", side_effect=SystemExit(1)
-            ) as mock_exit,
+            patch("webterm.terminal_session.os.execvp", side_effect=OSError()) as mock_execvp,
+            patch("webterm.terminal_session.os._exit", side_effect=SystemExit(1)) as mock_exit,
             pytest.raises(SystemExit),
         ):
             await session.open()
@@ -209,9 +203,7 @@ class TestTerminalSession:
         with (
             patch("webterm.terminal_session.pty.fork", return_value=(pty.CHILD, 123)),
             patch("webterm.terminal_session.shlex.split", side_effect=ValueError("bad")),
-            patch(
-                "webterm.terminal_session.os._exit", side_effect=SystemExit(1)
-            ) as mock_exit,
+            patch("webterm.terminal_session.os._exit", side_effect=SystemExit(1)) as mock_exit,
             pytest.raises(SystemExit),
         ):
             await session.open()