diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bfe19439f..e8d633615 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -52,7 +52,7 @@ jobs:
   suite:
     runs-on: ubuntu-latest
     # A hung test must turn red in minutes, not burn GitHub's 6-hour default.
-    timeout-minutes: 60
+    timeout-minutes: 120
     steps:
       - uses: actions/checkout@v4
         with:
diff --git a/src/toad/session_scope.py b/src/toad/session_scope.py
index d8d4004f1..22e5d3731 100644
--- a/src/toad/session_scope.py
+++ b/src/toad/session_scope.py
@@ -328,6 +328,13 @@ class SessionScope(NavigationOwner, ProjectPathOwner, ToadNode):
     footer_compact = False
     presentation: OperationalSessionPresentation
 
+    async def _pre_process(self) -> bool:
+        """Textual tears a failed start down; the workspace must not keep the dead tree."""
+        started = await super()._pre_process()
+        if not started:
+            self.app.workspace_sessions.detach(self.id)
+        return started
+
     def matches_launch(self, agent_identity: str, session_id: str) -> bool:
         return False
 
diff --git a/src/toad/widget_actions.py b/src/toad/widget_actions.py
index da7712683..f38f140fc 100644
--- a/src/toad/widget_actions.py
+++ b/src/toad/widget_actions.py
@@ -17,6 +17,7 @@
 from textual._activation import PrimaryActivation
 from textual._callback import invoke
 from textual.keys import KeyDeclaration, KeyDeclarationType
+from textual.navigation import SelectCursor
 from textual.widgets.text_area import EditingMode
 from textual.dom import DOMNode
 from toad.app_node import ToadNode
@@ -331,6 +332,11 @@ class OpenSelectedAction(VisibleAction):
     title = "Open"
     keys = {EditingMode: ("enter",)}
 
+    @classmethod
+    def permits_key_overlap(cls, other: KeyDeclarationType) -> bool:
+        """Opening the row is what selecting the cursor means on a list that opens rows."""
+        return issubclass(other, SelectCursor)
+
     async def apply(self, context: OpensSelected) -> None:
         context.open_selected()
 
diff --git a/src/toad/workspace_sessions.py b/src/toad/workspace_sessions.py
index 4f589477a..d6ddababe 100644
--- a/src/toad/workspace_sessions.py
+++ b/src/toad/workspace_sessions.py
@@ -165,6 +165,10 @@ async def retire(self):
         return self
 
 
+class SessionStartFailed(RuntimeError):
+    """A session's own startup failed; the app has already shown that error."""
+
+
 class WorkspaceSessions:
     def __init__(self, app: "ToadApp") -> None:
         self.app = app
@@ -196,6 +200,8 @@ async def prepare(self, identity: str) -> "SessionScope":
         self.views[identity] = view
         host = self.app.workspace_screen.query_one("#workspace-session-host", Container)
         await host.mount(view)
+        if identity not in self.views:
+            raise SessionStartFailed(identity)
         return view
 
     async def select(self, identity: str) -> "SessionScope":
diff --git a/tests/support/core_adapters/mcp_permission_observer.py b/tests/support/core_adapters/mcp_permission_observer.py
index 6bcc9658d..9490b7dc8 100644
--- a/tests/support/core_adapters/mcp_permission_observer.py
+++ b/tests/support/core_adapters/mcp_permission_observer.py
@@ -102,7 +102,7 @@ async def request_permission(self, *, session_id, tool_call, options, **kwargs):
                 previous = self.view
                 presentation = self.session.presentation
                 await presentation.retire(self.session)
-                await presentation.evict()
+                await presentation.evict(self.session)
                 assert request.pending and not self.agent.controller.surface.owns(previous)
                 assert not previous.is_mounted and presentation.sources.agent is self.agent
                 await presentation.prepare(self.session)
diff --git a/tests/textual/test_hidden_session_retirement.py b/tests/textual/test_hidden_session_retirement.py
index fdf1135ff..92ac5d6c4 100644
--- a/tests/textual/test_hidden_session_retirement.py
+++ b/tests/textual/test_hidden_session_retirement.py
@@ -2,7 +2,6 @@
 
 from agent_comms.repo import Checkout
 from collections import Counter
-from pathlib import Path
 import sys
 
 from agent_comms.comms import Comms
@@ -34,7 +33,7 @@ async def open_hidden_sessions(workspace, ui, owners):
     first = ui.selected_tab
 
     def source(owner):
-        return MainScreen.from_thread(Path(owner.worktree), str(workspace.comms.root), owner.incarnation)
+        return MainScreen.from_thread(owner.worktree, str(workspace.comms.root), owner.incarnation)
 
     modes = {}
     for owner in owners[1:]:
diff --git a/tests/textual/test_initial_prompt_handoff.py b/tests/textual/test_initial_prompt_handoff.py
index 9f1151b00..b93029ad9 100644
--- a/tests/textual/test_initial_prompt_handoff.py
+++ b/tests/textual/test_initial_prompt_handoff.py
@@ -2,6 +2,7 @@
 conversation widget being evicted and remounted, and keeps the editor's document and undo history."""
 
 import asyncio
+from agent_comms.repo import Checkout
 from collections import Counter
 
 
@@ -41,7 +42,7 @@ def observed(self, event, subscription):
 async def test_a_pending_initial_prompt_is_published_once_across_eviction_and_the_draft_and_undo_survive(workspace):
     async with workspace.app(size=(110, 35)) as ui:
         app, _pilot = ui.textual
-        owner = ObservedLaunchScreen(workspace.project, initial_prompt="INITIAL_LOCAL_UI_EVENT")
+        owner = ObservedLaunchScreen(Checkout(workspace.project), initial_prompt="INITIAL_LOCAL_UI_EVENT")
         await app.session_navigation.new(await saved_tab(app), lambda: owner)
         await owner.wait_content_ready()
         await asyncio.wait_for(owner.publication.wait(), 12)
@@ -60,7 +61,7 @@ async def test_a_pending_initial_prompt_is_published_once_across_eviction_and_th
         owner.publication.clear()
         await app.session_navigation.new(await saved_tab(app), lambda: MainScreen(app.project_dir))
         await app.selected_session.wait_content_ready()
-        await owner.presentation.evict()
+        await owner.presentation.evict(owner)
         assert view._initial_prompt is None
         assert owner.presentation.state.initial_prompt == "NEWEST_PENDING_LOCAL_UI_EVENT"
         assert owner.presentation.widget is None
@@ -84,7 +85,7 @@ async def test_a_pending_initial_prompt_is_published_once_across_eviction_and_th
         # The consumed value must stay absent on another eviction.
         await app.session_navigation.new(await saved_tab(app), lambda: MainScreen(app.project_dir))
         await app.selected_session.wait_content_ready()
-        await owner.presentation.evict()
+        await owner.presentation.evict(owner)
         assert owner.presentation.state.initial_prompt is None
         await ui.select_tab(owner.id)
         await ui.step()
diff --git a/tests/textual/test_keymap_model.py b/tests/textual/test_keymap_model.py
index 986a58025..1166d1969 100644
--- a/tests/textual/test_keymap_model.py
+++ b/tests/textual/test_keymap_model.py
@@ -12,17 +12,17 @@ def test_saved_remaps_keep_modes_independent_and_reset_to_the_declaration():
     catalog = KeymapCatalog.capture(KeyMode.members_with(KeyMode))
     ordinary = KeymapRow.of(KeymapAction(), Standard)
     normal = KeymapRow.of(KeymapAction(), VimNormal)
-    keymap = Keymap().changed(normal, ("f7",))
+    keymap = Keymap().changed(normal, ("f18",))
     applied = []
     settings = SavedSettings(applied=applied.append)
     settings.set(SETTINGS.ui.keymap.bindings, keymap.bindings)
     loaded = SavedSettings(settings.document()).current.ui.keymap
     assert [setting.path for setting in applied] == [SETTINGS.ui.keymap.bindings.bind(settings.state).path]
-    assert catalog.effective(normal, loaded) == ("f7",)
+    assert catalog.effective(normal, loaded) == ("f18",)
     assert catalog.effective(ordinary, loaded) == catalog.defaults(ordinary)
     assert catalog.effective(normal, loaded.reset(normal)) == catalog.defaults(normal)
     with pytest.raises(ValueError, match="Commander.*Keymap|Keymap.*Commander"):
-        loaded.changed(KeymapRow.of(CommanderAction(), VimNormal), ("f7",))
+        loaded.changed(KeymapRow.of(CommanderAction(), VimNormal), ("f18",))
 
 
 def test_an_empty_override_unbinds_and_survives_saving_until_reset():
@@ -44,7 +44,7 @@ def test_defaults_allow_the_declared_alternatives_in_every_mode():
 def test_reset_cannot_reintroduce_a_collision_and_duplicate_rows_are_refused():
     catalog = KeymapCatalog.capture(KeyMode.members_with(KeyMode))
     menu = KeymapRow.of(KeymapAction(), Standard)
-    keymap = Keymap().changed(menu, ("f7",))
+    keymap = Keymap().changed(menu, ("f18",))
     keymap = keymap.changed(KeymapRow.of(CommanderAction(), Standard), catalog.defaults(menu))
     with pytest.raises(ValueError, match="Key conflict"):
         keymap.reset(menu)
diff --git a/tests/textual/test_keymap_screen.py b/tests/textual/test_keymap_screen.py
index 5b9572131..8aa31a66f 100644
--- a/tests/textual/test_keymap_screen.py
+++ b/tests/textual/test_keymap_screen.py
@@ -51,7 +51,7 @@ async def test_f1_menu_remaps_itself_saves_and_refuses_a_conflict(workspace, mod
         table = app.screen.query_one(DataTable)
         assert table.size.height > table.header_height, "The command rows must have visible space"
         await choose(ui, KeymapAction(), mode)
-        app.screen.query_one("#keymap-keys", Input).value = "f7"
+        app.screen.query_one("#keymap-keys", Input).value = "f18"
         await ui.pilot.click("#keymap-apply")
         await ui.until(lambda: KeymapAction.binding_id(mode().binding_mode) in app._keymap,
                        why="the saved menu remap")
@@ -67,10 +67,10 @@ async def test_f1_menu_remaps_itself_saves_and_refuses_a_conflict(workspace, mod
         await ui.until(lambda: app.screen is app.workspace_screen, why="the keymap menu closed")
         await ui.press("f1")
         assert app.screen is app.workspace_screen
-        await ui.press("f7")
+        await ui.press("f18")
         await ui.until(lambda: isinstance(app.screen, KeymapScreen), why="the remapped menu key")
         await choose(ui, CommanderAction(), mode)
-        app.screen.query_one("#keymap-keys", Input).value = "f7"
+        app.screen.query_one("#keymap-keys", Input).value = "f18"
         await ui.pilot.click("#keymap-apply")
         await ui.until(lambda: "Key conflict" in str(app.screen.query_one("#keymap-status", Static).render()),
                        why="the colliding remap refusal")
@@ -80,7 +80,7 @@ async def test_f1_menu_remaps_itself_saves_and_refuses_a_conflict(workspace, mod
     async with workspace.app(size=size) as reopened:
         await reopened.press("f1")
         assert reopened.app.screen is reopened.app.workspace_screen
-        await reopened.press("f7")
+        await reopened.press("f18")
         await reopened.until(lambda: isinstance(reopened.app.screen, KeymapScreen),
                              why="the saved menu remap after restarting the app")
 
diff --git a/tests/textual/test_plan_display.py b/tests/textual/test_plan_display.py
index 73124e037..11876a736 100644
--- a/tests/textual/test_plan_display.py
+++ b/tests/textual/test_plan_display.py
@@ -108,7 +108,7 @@ async def test_an_empty_plan_resets_the_view_and_a_retired_sidebar_shows_later_p
         advance(workspace, 0)
         await ui.until(lambda: plan.all_complete, why="the completed plan")
         advance(workspace, 1)
-        await sidebar.evict()
+        await sidebar.evict(ui.textual[0].selected_session)
         assert not sidebar.panels
         await ui.until(lambda: not plan.entries and not plan.all_complete, why="the plan to reset")
         await ui.until(lambda: painted_text(plan, "No plan yet"), why="the empty plan painted")
diff --git a/tests/textual/test_session_start_failure.py b/tests/textual/test_session_start_failure.py
new file mode 100644
index 000000000..95f5e3ae3
--- /dev/null
+++ b/tests/textual/test_session_start_failure.py
@@ -0,0 +1,24 @@
+"""Textual-facing: a session whose mount fails leaves the workspace, instead of crashing later as a missing sidebar."""
+
+from agent_comms.repo import Checkout
+import pytest
+
+from support.ui import saved_tab
+
+from toad.screens.main import MainScreen
+from toad.workspace_sessions import SessionStartFailed
+
+
+class FailsToStart(MainScreen):
+    def on_mount(self) -> None:
+        raise ValueError("START_FAILURE")
+
+
+async def test_a_failed_mount_names_the_session_and_leaves_no_dead_view(workspace):
+    async with workspace.app(size=(110, 35)) as ui:
+        app, _ = ui.textual
+        before = set(app.workspace_sessions.views)
+        with pytest.raises(SessionStartFailed):
+            await app.session_navigation.new(
+                await saved_tab(app), lambda: FailsToStart(Checkout(workspace.project)))
+        assert set(app.workspace_sessions.views) == before
diff --git a/tests/textual/test_sidebar_retirement.py b/tests/textual/test_sidebar_retirement.py
index 96b981f39..bf63a99da 100644
--- a/tests/textual/test_sidebar_retirement.py
+++ b/tests/textual/test_sidebar_retirement.py
@@ -140,7 +140,7 @@ async def exercise(ui, screen, root):
     assert tree_ref() is sidebar.query_one(ProjectDirectoryTree)
     await sidebar.prepare_presentation()
     assert tree_ref() is sidebar.query_one(ProjectDirectoryTree)
-    await sidebar.evict()
+    await sidebar.evict(screen)
     assert not sidebar.panels and not sidebar._panels_loaded
     assert screen._project_panel is None
     assert not tuple(viewport.children)
@@ -214,7 +214,7 @@ async def test_panels_rebuild_after_eviction_while_collapsed(workspace):
     async with workspace.app(size=(130, 44), application=InstalledApp) as ui:
         screen = await started(workspace, ui)
         sidebar = screen.query_one(SessionThreadSidebar)
-        await sidebar.evict()
+        await sidebar.evict(screen)
         sidebar.reveal()
         sidebar.collapsed = True
         await ui.step(0.05)
@@ -231,7 +231,7 @@ async def test_panels_show_the_current_project_after_the_source_project_changes_
     async with workspace.app(size=(130, 44), application=InstalledApp) as ui:
         screen = await started(workspace, ui)
         sidebar = await reveal(ui, screen)
-        await sidebar.evict()
+        await sidebar.evict(screen)
         replacement = workspace.project.parent / "replacement-project"
         replacement.mkdir()
         (replacement / "new-source.txt").write_text("Current filesystem")
@@ -254,7 +254,7 @@ async def test_leaving_a_view_stops_its_sidebar_hydration(workspace):
         sidebar = await reveal(ui, screen)
         # The next tab is saved first, so leaving the view does not wait on the database.
         tab = await saved_tab(app)
-        await sidebar.evict()
+        await sidebar.evict(screen)
         sidebar._start_hydration()
         assert sidebar._panels_loading
         workers = tuple(
diff --git a/tests/textual/test_sidebar_state_across_views.py b/tests/textual/test_sidebar_state_across_views.py
index dd8d10d3a..7f15805c5 100644
--- a/tests/textual/test_sidebar_state_across_views.py
+++ b/tests/textual/test_sidebar_state_across_views.py
@@ -1,5 +1,6 @@
 """Textual-facing: the channels sidebar's expansion, scroll position and range anchor survive switching between views, painted identically from its first ready frame."""
 
+from agent_comms.repo import Checkout
 from support.stylesheets import INSTALLED
 from support.textual_steps import channel_roster
 
@@ -75,7 +76,7 @@ async def test_sidebar_expansion_scroll_and_anchor_survive_view_changes(workspac
         worker = await app.session_navigation.new(
             MailboxTab(workspace.comms.registry.require("worker").incarnation, str(workspace.comms.root)),
             lambda: MainScreen.from_thread(
-                workspace.project,
+                Checkout(workspace.project),
                 str(workspace.comms.root),
                 workspace.comms.registry.require("worker").incarnation,
             )
diff --git a/tests/textual/test_tab_return_keeps_blocks.py b/tests/textual/test_tab_return_keeps_blocks.py
index 8d29fcc1e..d7f1c5b50 100644
--- a/tests/textual/test_tab_return_keeps_blocks.py
+++ b/tests/textual/test_tab_return_keeps_blocks.py
@@ -47,7 +47,7 @@ async def test_evicted_saved_tab_restores_before_its_first_published_frame(works
         document, undo = editor.document, editor.history
         old_view = ui.conversation
         other = await ui.new_session()
-        await owner.presentation.evict()
+        await owner.presentation.evict(owner)
         assert owner.presentation.widget is None
         assert owner.presentation.transcript.documents