feat: sandbox toggles in New Session dialog, gated on bwrap availability

Adds sandbox_available param to NewSessionScreen, renders Switch/Select/
Switch widgets for sandbox on/off, filesystem access (rw/ro), and network
toggle. When bwrap is unavailable the switch is disabled and a warning label
is shown. The _policy_from staticmethod maps widget values to SandboxPolicy.
The result tuple gains SandboxPolicy | None as its fifth element. app.py
passes sandbox_available=sandbox.is_available() when opening the dialog and
unpacks the new element to forward sandbox= to create_session.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/hqt/tui/app.py

@@ -10,6 +10,7 @@ from textual.screen import ModalScreen
 from textual.theme import Theme
 from textual.widgets import Footer
 
+from hqt import sandbox
 from hqt.config import get_settings
 from hqt.git import worktree
 from hqt.db.engine import ensure_db, get_engine, get_session_factory
@@ -255,10 +256,10 @@ class HqtApp(App):
         project_path = project.path
 
         def on_dismiss(
-            result: tuple[str, str, str | None, str | None] | None,
+            result: tuple[str, str, str | None, str | None, object] | None,
         ) -> None:
             if result:
-                harness_name, nickname, model, worktree_branch = result
+                harness_name, nickname, model, worktree_branch, sandbox_policy = result
 
                 async def _do() -> None:
                     create_result = await self._sessions().create_session(
@@ -267,6 +268,7 @@ class HqtApp(App):
                         nickname,
                         model,
                         worktree_branch=worktree_branch,
+                        sandbox=sandbox_policy,
                     )
                     if not create_result.spawn_ok:
                         first_line = next(
@@ -296,7 +298,14 @@ class HqtApp(App):
             except Exception as exc:  # noqa: BLE001 - keep the worker from crashing the TUI
                 log.warning("is_git_repo check failed for %s: %s", project_path, exc)
                 is_git_repo = False
-            self.push_screen(NewSessionScreen(harness_names, is_git_repo), on_dismiss)
+            self.push_screen(
+                NewSessionScreen(
+                    harness_names,
+                    is_git_repo,
+                    sandbox_available=sandbox.is_available(),
+                ),
+                on_dismiss,
+            )
 
         self.run_worker(_open())
 

src/hqt/tui/screens/new_session.py

@@ -1,15 +1,24 @@
 from textual.app import ComposeResult
 from textual.containers import Horizontal, Vertical
 from textual.screen import ModalScreen
-from textual.widgets import Button, Checkbox, Input, Label, Select
+from textual.widgets import Button, Checkbox, Input, Label, Select, Switch
 
 from hqt.git import worktree
+from hqt.sandbox import SandboxPolicy
 
 
-class NewSessionScreen(ModalScreen[tuple[str, str, str | None, str | None] | None]):
+class NewSessionScreen(
-    def __init__(self, harness_names: list[str], is_git_repo: bool) -> None:
+    ModalScreen[tuple[str, str, str | None, str | None, SandboxPolicy | None] | None]
+):
+    def __init__(
+        self,
+        harness_names: list[str],
+        is_git_repo: bool = False,
+        sandbox_available: bool = False,
+    ) -> None:
         self.harness_names = harness_names
         self._is_git_repo = is_git_repo
+        self.sandbox_available = sandbox_available
         super().__init__()
 
     def compose(self) -> ComposeResult:
@@ -43,6 +52,26 @@ class NewSessionScreen(ModalScreen[tuple[str, str, str | None, str | None] | Non
             branch_input = Input(placeholder="branch name", id="branch-input")
             branch_input.display = False
             yield branch_input
+            yield Label("Sandboxed (bubblewrap):")
+            yield Switch(
+                id="sandbox-switch",
+                value=False,
+                disabled=not self.sandbox_available,
+            )
+            if not self.sandbox_available:
+                yield Label(
+                    "bubblewrap not found — run `hqt doctor`",
+                    id="sandbox-warning",
+                )
+            yield Label("Filesystem access:")
+            yield Select(
+                [("Read-write", "rw"), ("Read-only", "ro")],
+                id="fs-select",
+                value="rw",
+                allow_blank=False,
+            )
+            yield Label("Network:")
+            yield Switch(id="net-switch", value=True)
             with Horizontal(classes="dialog-actions"):
                 yield Button("OK", variant="primary", id="ok-btn")
                 yield Button("Cancel", id="cancel-btn")
@@ -71,6 +100,13 @@ class NewSessionScreen(ModalScreen[tuple[str, str, str | None, str | None] | Non
         # can be completed from the keyboard without reaching for the mouse.
         self._submit()
 
+    @staticmethod
+    def _policy_from(enabled: bool, fs: str, net: bool) -> SandboxPolicy | None:
+        """Pure mapping from widget values to a policy (None when disabled)."""
+        if not enabled:
+            return None
+        return SandboxPolicy(fs=fs, net=net)
+
     def _submit(self) -> None:
         harness = self.query_one("#harness-select", Select).value
         nickname = self.query_one("#nickname-input", Input).value
@@ -86,7 +122,12 @@ class NewSessionScreen(ModalScreen[tuple[str, str, str | None, str | None] | Non
                 branch_input.focus()
                 return
 
+        enabled = self.query_one("#sandbox-switch", Switch).value
+        fs = self.query_one("#fs-select", Select).value
+        net = self.query_one("#net-switch", Switch).value
+        policy = self._policy_from(bool(enabled), str(fs), bool(net))
+
         if harness and harness != Select.BLANK:
-            self.dismiss((str(harness), nickname, model, worktree_branch))
+            self.dismiss((str(harness), nickname, model, worktree_branch, policy))
         else:
             self.dismiss(None)

tests/test_tui.py

@@ -292,7 +292,7 @@ async def test_new_session_on_dismiss_sequential_create_then_refresh():
         call_order: list[str] = []
 
         async def fake_create(
-            project_id, harness_name, nickname, model, worktree_branch=None
+            project_id, harness_name, nickname, model, worktree_branch=None, sandbox=None
         ):
             # Brief yield so that, if two separate workers were used, the list
             # worker would be able to start and record "list" before this
@@ -324,7 +324,7 @@ async def test_new_session_on_dismiss_sequential_create_then_refresh():
             await pilot.pause()
 
         # The NewSessionScreen is now on top; dismiss it with a valid result tuple.
-        app.screen.dismiss(("claude", "mynick", None, None))
+        app.screen.dismiss(("claude", "mynick", None, None, None))
         await pilot.pause()
 
         # Wait for the worker spawned by on_dismiss to finish deterministically.
@@ -396,7 +396,7 @@ async def test_new_session_on_dismiss_notifies_on_spawn_failure():
                 await app.workers.wait_for_complete()
                 await pilot.pause()
 
-                app.screen.dismiss(("claude", "mynick", None, None))
+                app.screen.dismiss(("claude", "mynick", None, None, None))
                 await pilot.pause()
                 await app.workers.wait_for_complete()
                 await pilot.pause()
@@ -467,7 +467,7 @@ async def test_new_session_on_dismiss_no_notify_on_success():
                 await app.workers.wait_for_complete()
                 await pilot.pause()
 
-                app.screen.dismiss(("claude", "mynick", None, None))
+                app.screen.dismiss(("claude", "mynick", None, None, None))
                 await pilot.pause()
                 await app.workers.wait_for_complete()
                 await pilot.pause()
@@ -582,7 +582,7 @@ async def test_new_session_enter_in_input_submits_dialog():
         await pilot.press("enter")
         await pilot.pause()
 
-        assert results == [("claude", "mywork", None, None)], f"got {results}"
+        assert results == [("claude", "mywork", None, None, None)], f"got {results}"
 
 
 # ---------------------------------------------------------------------------
@@ -1291,7 +1291,7 @@ async def test_new_session_worktree_unchecked_returns_none_branch():
         app.screen.query_one("#nickname-input", Input).value = "mywork"
         app.screen.query_one("#ok-btn", Button).press()
         await pilot.pause()
-        assert results == [("claude", "mywork", None, None)], f"got {results}"
+        assert results == [("claude", "mywork", None, None, None)], f"got {results}"
 
 
 @pytest.mark.asyncio
@@ -1316,7 +1316,7 @@ async def test_new_session_worktree_checked_uses_typed_branch():
         branch.value = "feature-x"
         app.screen.query_one("#ok-btn", Button).press()
         await pilot.pause()
-        assert results == [("claude", "My Work", None, "feature-x")], f"got {results}"
+        assert results == [("claude", "My Work", None, "feature-x", None)], f"got {results}"
 
 
 @pytest.mark.asyncio
@@ -1338,7 +1338,7 @@ async def test_new_session_worktree_checked_blank_branch_slugifies_nickname():
         app.screen.query_one("#branch-input", Input).value = ""
         app.screen.query_one("#ok-btn", Button).press()
         await pilot.pause()
-        assert results == [("claude", "Cool Feature!", None, "cool-feature")], (
+        assert results == [("claude", "Cool Feature!", None, "cool-feature", None)], (
             f"got {results}"
         )
 
@@ -1504,3 +1504,46 @@ async def test_delete_non_worktree_session_does_not_push_modal():
         verify_db = app._db_factory()
         assert verify_db.get(Session, sess_id) is None
         verify_db.close()
+
+
+# ---------------------------------------------------------------------------
+# Task 6: Sandbox controls in NewSessionScreen
+# ---------------------------------------------------------------------------
+
+
+def test_policy_from_disabled_returns_none():
+    from hqt.tui.screens.new_session import NewSessionScreen
+
+    assert NewSessionScreen._policy_from(False, "rw", True) is None
+
+
+def test_policy_from_enabled_builds_policy():
+    from hqt.sandbox import SandboxPolicy
+    from hqt.tui.screens.new_session import NewSessionScreen
+
+    p = NewSessionScreen._policy_from(True, "ro", False)
+    assert p == SandboxPolicy(fs="ro", net=False)
+
+
+@pytest.mark.asyncio
+async def test_sandbox_switch_disabled_when_unavailable():
+    from hqt.tui.screens.new_session import NewSessionScreen
+    from textual.widgets import Switch
+
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        app.push_screen(NewSessionScreen(["claude"], is_git_repo=False, sandbox_available=False))
+        await pilot.pause()
+        assert app.screen.query_one("#sandbox-switch", Switch).disabled is True
+
+
+@pytest.mark.asyncio
+async def test_sandbox_switch_enabled_when_available():
+    from hqt.tui.screens.new_session import NewSessionScreen
+    from textual.widgets import Switch
+
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        app.push_screen(NewSessionScreen(["claude"], is_git_repo=False, sandbox_available=True))
+        await pilot.pause()
+        assert app.screen.query_one("#sandbox-switch", Switch).disabled is False