feat(tui): grid layout + auto-growing scroll input

packages/cothis-tui/src/cothis/tui.py

@@ -1,14 +1,17 @@
 """``cothis.tui`` — Textual TUI core (#228).
 
-Adaptive pane layout:
-
-- ``SessionList`` (left): sessions from the session table. Auto-hidden
-  in single-session mode (≤1 session listed or attached) so
-  ``ConversationView`` takes the full width — the sidebar only appears
-  when the user can actually switch among sessions.
-- ``ConversationView`` (center): scrollable Markdown + tool-call cards.
-- ``TextArea`` input (bottom, ``id="input"``): multiline input with Ctrl+Enter to send.
-- ``CothisFooter`` (very bottom, ``id="footer"``): one-line status bar —
+Grid layout (four rows, no dock hacks — every widget is placed by the
+grid, ``Header { dock: none }`` overrides its default top-dock):
+
+- row 1 ``Header`` (1 row): app title bar.
+- row 2 ``#main`` (``1fr``): ``SessionList`` (left) + ``ConversationView``
+  (center). The sidebar is auto-hidden in single-session mode (≤1 session
+  listed or attached) so ``ConversationView`` takes the full width — the
+  sidebar only appears when the user can actually switch among sessions.
+- row 3 ``TextArea`` input (``auto``): multiline input with Ctrl+Enter to
+  send. Auto-grows with content (``min-height: 3``) up to ``max-height: 8``,
+  then scrolls internally — a long prompt never squeezes the conversation.
+- row 4 ``CothisFooter`` (1 row): one-line status bar —
   model / session short-id / context pressure / active skills / run-state.
 
 Stream routing per the design-review sign-off (#228, 2026-07-24):
@@ -697,7 +700,6 @@ class CothisFooter(Static):
     DEFAULT_CSS = """
     CothisFooter#footer {
         height: 1;
-        dock: bottom;
         background: $boost;
         color: $text-disabled;
         padding: 0 1;
@@ -723,18 +725,22 @@ class CothisApp(App):
     TITLE = "cothis"
     CSS = """
     Screen {
-        layout: vertical;
+        layout: grid;
+        grid-size: 1 4;
+        grid-rows: 1 1fr auto 1;
+        grid-columns: 1fr;
     }
-    #main {
-        height: 1fr;
+    Header {
+        dock: none;
     }
     SessionList > ListItem.active-session {
         background: $boost;
         text-style: bold;
     }
     TextArea#input {
-        height: 3;
-        dock: bottom;
+        height: auto;
+        min-height: 3;
+        max-height: 8;
         border: round $secondary;
     }
     """

pyproject.toml

@@ -4,6 +4,14 @@ members = ["packages/*"]
 [tool.uv]
 package = false
 
+# Point ty (CLI + LSP) at the uv workspace venv so third-party imports
+# resolve everywhere — including the LSP auxiliary scanner, which launches
+# ``ty server`` from a cwd where auto-discovery misses ``.venv``. The
+# directory (not interpreter) form keeps this portable across OSes: ty
+# locates ``bin/python`` / ``Scripts/python.exe`` inside the venv itself.
+[tool.ty.environment]
+python = ".venv"
+
 [dependency-groups]
 dev = [
     "pytest>=9.1.1",

tests/test_tui.py

@@ -31,6 +31,62 @@ async def test_app_launches_with_three_panes() -> None:
         assert app.query_one("#input") is not None
 
 
+@pytest.mark.asyncio
+async def test_grid_layout_stacks_panes_vertically() -> None:
+    """The four grid rows stack top-to-bottom: header / main / input / footer.
+
+    The grid (``grid-rows: 1 1fr auto 1``) replaces the old dock-based
+    layout; every pane must be placed by the grid, so the footer sits
+    BENEATH the input (not docked above it) and the conversation row owns
+    the remaining height.
+    """
+    from cothis.tui import ConversationView, CothisApp, CothisFooter
+
+    app = CothisApp()
+    async with app.run_test(size=(100, 40)) as pilot:
+        await pilot.pause()
+        header = app.query_one("Header")
+        main = app.query_one("#main")
+        conv = app.query_one(ConversationView)
+        input_box = app.query_one("#input")
+        footer = app.query_one(CothisFooter)
+        assert header.region.y < main.region.y < input_box.region.y < footer.region.y
+        # Conversation gets the full remaining height: taller than the
+        # input and footer combined, and it spans the full width in
+        # single-session mode (sidebar hidden).
+        assert conv.region.height > input_box.region.height + footer.region.height
+        assert conv.region.width == app.size.width
+
+
+@pytest.mark.asyncio
+async def test_input_auto_grows_then_scrolls_internally() -> None:
+    """The input ``TextArea`` grows with content, then scrolls past a cap.
+
+    ``height: auto`` sizes the box to the prompt (min 3 rows); past
+    ``max-height`` it stops growing and scrolls internally, so a long
+    prompt never squeezes the conversation out of the 1fr row.
+    """
+    from textual.widgets import TextArea
+
+    from cothis.tui import CothisApp
+
+    app = CothisApp()
+    async with app.run_test(size=(100, 40)) as pilot:
+        await pilot.pause()
+        input_box = app.query_one("#input", TextArea)
+        conv = app.query_one("ConversationView")
+        idle_conv_height = conv.region.height
+        idle_input_height = input_box.region.height
+        assert idle_input_height >= 3  # min-height floor
+        input_box.text = "\n".join(f"line {i}" for i in range(30))
+        await pilot.pause()
+        assert input_box.region.height > idle_input_height  # grew
+        assert input_box.region.height <= 8  # capped at max-height
+        assert input_box.max_scroll_y > 0  # internal scroll past the cap
+        assert conv.region.height < idle_conv_height  # conversation shrank
+
+
+
 @pytest.mark.asyncio
 async def test_conversation_view_appends_text_delta() -> None:
     """``append_delta(kind='text', ...)`` accumulates into renderable."""

tests/test_tui_pty.py

@@ -38,8 +38,9 @@
 def _spawn_tui_pty(cols: int = 90, rows: int = 24) -> tuple[subprocess.Popen, int]:
     """Spawn ``python -m cothis.tui`` on a fresh PTY; return (proc, master_fd).
 
-    The slave is sized via ``TIOCSWINSZ`` so Textual lays out the 3 panes
-    (input docked at the bottom) instead of falling back to a 0x0 PTY.
+    The slave is sized via ``TIOCSWINSZ`` so Textual lays out the 4 grid rows
+    (header / conversation / input / footer) instead of falling back to a
+    0x0 PTY.
     ``TERM=xterm-256color`` makes Textual pick its real terminal driver —
     the code path the bug lived in.
 
@@ -51,9 +52,9 @@ def _spawn_tui_pty(cols: int = 90, rows: int = 24) -> tuple[subprocess.Popen, in
     import pty
     import termios
 
-    openpty = getattr(pty, "openpty")
-    ioctl = getattr(fcntl, "ioctl")
-    tiocswinsz = getattr(termios, "TIOCSWINSZ")
+    openpty = getattr(pty, "openpty")  # noqa: B009 — deliberate: Windows ty-safe member access
+    ioctl = getattr(fcntl, "ioctl")  # noqa: B009 — deliberate: Windows ty-safe member access
+    tiocswinsz = getattr(termios, "TIOCSWINSZ")  # noqa: B009 — deliberate: Windows ty-safe member access
 
     master, slave = openpty()
     ioctl(slave, tiocswinsz, struct.pack("HHHH", rows, cols, 0, 0))