fix(tui): make the mount prompt clickable, and skip the mount instead of abandoning the scan (#1015)

* make the working-directory prompt answer the mouse

Its Confirm and Cancel were drawn as buttons and did nothing when clicked: the
modal mouse handler had a case for every dialog except this one, so a click fell
through and the scan sat waiting on an answer the user believed they had given.
Only the keyboard could answer it.

The prompt is docked in a corner rather than centered, so it also needs its own
bounds; the centered ones every other dialog uses would have put the buttons in
the wrong place. Those bounds now come from the same placement cornerOverlay
draws with.

Two returns that hand back the model alongside a call that mutates it are now
sequenced explicitly. They work, but only because the compiler happens to
evaluate the call first, and one of them is what puts the prompt back in the
composer when the mount is declined.

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

* skip the mount instead of abandoning the scan

Declining the working-directory prompt threw the whole launch away and dropped
back to the start screen, which is a lot to lose for answering one question
about one directory. The two answers are now about the directory alone: mount it,
or run without it. The prompt is the whole of the input either way.

The buttons say which is which - Mount and Skip rather than Confirm and Cancel -
and the prompt says what skipping costs.

A run with neither target nor directory is a real run, so two things follow it.
It can be resumed: its instruction is what drives it, and that is in the run
record. And it tells the agent plainly that it has neither, because an agent
given no scope goes looking for the one it assumes it was meant to have.

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

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_tui_backend_controller.py

@@ -234,12 +234,11 @@ async def test_confirming_the_mount_starts_the_scan_without_a_target() -> None:
 
 
 @pytest.mark.asyncio
-async def test_declining_the_mount_returns_to_the_start_screen() -> None:
-    started = False
+async def test_declining_the_mount_runs_without_one() -> None:
+    started: list[bool] = []
 
-    async def start(_verify: bool = True) -> None:
-        nonlocal started
-        started = True
+    async def start(verify: bool = True) -> None:
+        started.append(verify)
 
     os.environ["STRIX_LLM"] = "anthropic/claude-sonnet-4"
     os.environ["ANTHROPIC_API_KEY"] = "test-key"
@@ -250,14 +249,34 @@ async def test_declining_the_mount_returns_to_the_start_screen() -> None:
     result = await controller.handle("setup.confirm_mount", {"approved": False})
 
     assert result == {"approved": False}
-    # Nothing was prepared, so the session goes back to the start screen and can
-    # be launched again.
-    assert started is False
+    # Declining skips the directory; it does not abandon the scan.
+    assert started == [False]
     assert controller.workspace_mount is None
     assert controller.pending_workspace_mount is None
-    assert controller.setup_mode is True
-    assert controller.scan_started is False
-    assert controller.scan_state == "setup"
+    assert controller.setup_mode is False
+    assert controller.scan_started is True
+    assert controller.scan_state == "running"
+
+
+@pytest.mark.asyncio
+async def test_approving_the_mount_runs_with_it() -> None:
+    started: list[bool] = []
+
+    async def start(verify: bool = True) -> None:
+        started.append(verify)
+
+    os.environ["STRIX_LLM"] = "anthropic/claude-sonnet-4"
+    os.environ["ANTHROPIC_API_KEY"] = "test-key"
+    loader._cached = None
+    controller = TuiController(args(), on_start=start)
+    await controller.handle("setup.start", {"verify": False, "mount_working_dir": True})
+
+    result = await controller.handle("setup.confirm_mount", {"approved": True})
+
+    assert result == {"approved": True}
+    assert started == [False]
+    assert controller.workspace_mount == str(Path.cwd())
+    assert controller.scan_state == "running"
 
 
 @pytest.mark.asyncio