fix(tui): resolve format, AmbiguousStep, and coverage gaps in session persistence

- Apply ruff format to store.py (split multi-arg conn.execute calls) and
  steps file (collapse single-arg execute to one line)
- Fix AmbiguousStep: add literal quotes to @given/@then patterns so
  'a session with id "{session_id}"' is unambiguous vs the
  'in the database' variant; update all dependent then-steps consistently
- Mark if TYPE_CHECKING block with # pragma: no cover (never executed)
- Add scenario + step for default db_path to cover store.py lines 32-34
  (uses unittest.mock.patch on Path.home to avoid touching real homedir)

ISSUES CLOSED: #10648

features/steps/tui_session_persistence_steps.py

@@ -42,15 +42,13 @@ def step_database_has_tables(context: object) -> None:
     import sqlite3
 
     with sqlite3.connect(context.db_path) as conn:  # type: ignore
-        cursor = conn.execute(
-            "SELECT name FROM sqlite_master WHERE type='table'"
-        )
+        cursor = conn.execute("SELECT name FROM sqlite_master WHERE type='table'")
         tables = {row[0] for row in cursor.fetchall()}
         assert "sessions" in tables
         assert "active_session" in tables
 
 
-@given("a session with id {session_id} and transcript {transcript}")
+@given('a session with id "{session_id}" and transcript {transcript}')
 def step_create_session_with_transcript(
     context: object, session_id: str, transcript: str
 ) -> None:
@@ -63,7 +61,7 @@ def step_create_session_with_transcript(
     context.session = session  # type: ignore
 
 
-@given("a session with id {session_id}")
+@given('a session with id "{session_id}"')
 def step_create_session(context: object, session_id: str) -> None:
     """Create a session with the given id."""
     session = SessionView(session_id=session_id, transcript=[])
@@ -97,7 +95,7 @@ def step_set_active_session(context: object) -> None:
     context.store.set_active_session(context.session.session_id)  # type: ignore
 
 
-@then("the active session id is {session_id}")
+@then('the active session id is "{session_id}"')
 def step_verify_active_session(context: object, session_id: str) -> None:
     """Verify the active session id."""
     active = context.store.get_active_session()  # type: ignore
@@ -130,7 +128,7 @@ def step_verify_list_sessions(context: object) -> None:
     assert set(listed) == expected_ids
 
 
-@given("a session with id {session_id} in the database")
+@given('a session with id "{session_id}" in the database')
 def step_create_and_save_session(context: object, session_id: str) -> None:
     """Create and save a session."""
     session = SessionView(session_id=session_id, transcript=[])
@@ -184,7 +182,7 @@ def step_create_new_store_instance(context: object) -> None:
     context.new_store = TuiSessionStore(db_path=context.db_path)  # type: ignore
 
 
-@then("the active session is {session_id}")
+@then('the active session is "{session_id}"')
 def step_verify_new_store_active_session(context: object, session_id: str) -> None:
     """Verify the active session in the new store."""
     active = context.new_store.get_active_session()  # type: ignore
@@ -198,3 +196,17 @@ def step_verify_session_restored(context: object) -> None:
     assert loaded is not None
     assert loaded.session_id == context.session.session_id  # type: ignore
     assert loaded.transcript == context.session.transcript  # type: ignore
+
+
+@given("the TUI session store is created with default database path")
+def step_default_db_path(context: object) -> None:
+    """Initialize store using the default path, patching home to a temp dir."""
+    from unittest.mock import patch
+
+    temp_dir = tempfile.mkdtemp()
+    temp_home = Path(temp_dir)
+    with patch.object(Path, "home", return_value=temp_home):
+        context.store = TuiSessionStore()  # type: ignore
+    context.db_path = (  # type: ignore
+        temp_home / ".local" / "state" / "cleveragents" / "tui.db"
+    )

features/tui_session_persistence.feature

@@ -45,3 +45,7 @@ Feature: TUI Session Persistence
     And I create a new session store instance
     Then the active session is "last-session"
     And the session data is restored correctly
+
+  Scenario: Store uses default database path when none is specified
+    Given the TUI session store is created with default database path
+    Then the SQLite database file exists at ~/.local/state/cleveragents/tui.db

src/cleveragents/tui/persistence/store.py

@@ -8,7 +8,7 @@ from dataclasses import dataclass
 from pathlib import Path
 from typing import TYPE_CHECKING
 
-if TYPE_CHECKING:
+if TYPE_CHECKING:  # pragma: no cover
     from cleveragents.tui.app import SessionView
 
 
@@ -64,10 +64,13 @@ class TuiSessionStore:
         """
         with sqlite3.connect(self.db_path) as conn:
             transcript_json = json.dumps(session.transcript)
-            conn.execute("""
+            conn.execute(
+                """
                 INSERT OR REPLACE INTO sessions (session_id, transcript, updated_at)
                 VALUES (?, ?, CURRENT_TIMESTAMP)
-            """, (session.session_id, transcript_json))
+            """,
+                (session.session_id, transcript_json),
+            )
             conn.commit()
 
     def load_session(self, session_id: str) -> SessionView | None:
@@ -80,9 +83,12 @@ class TuiSessionStore:
             The SessionView if found, None otherwise
         """
         with sqlite3.connect(self.db_path) as conn:
-            cursor = conn.execute("""
+            cursor = conn.execute(
+                """
                 SELECT session_id, transcript FROM sessions WHERE session_id = ?
-            """, (session_id,))
+            """,
+                (session_id,),
+            )
             row = cursor.fetchone()
 
             if row is None:
@@ -92,6 +98,7 @@ class TuiSessionStore:
             transcript = json.loads(transcript_json)
             # Import here to avoid circular imports
             from cleveragents.tui.app import SessionView
+
             return SessionView(session_id=session_id_result, transcript=transcript)
 
     def set_active_session(self, session_id: str) -> None:
@@ -101,10 +108,13 @@ class TuiSessionStore:
             session_id: The ID of the session to set as active
         """
         with sqlite3.connect(self.db_path) as conn:
-            conn.execute("""
+            conn.execute(
+                """
                 INSERT OR REPLACE INTO active_session (id, session_id, updated_at)
                 VALUES (1, ?, CURRENT_TIMESTAMP)
-            """, (session_id,))
+            """,
+                (session_id,),
+            )
             conn.commit()
 
     def get_active_session(self) -> str | None:
@@ -139,9 +149,12 @@ class TuiSessionStore:
             session_id: The ID of the session to delete
         """
         with sqlite3.connect(self.db_path) as conn:
-            conn.execute("""
+            conn.execute(
+                """
                 DELETE FROM sessions WHERE session_id = ?
-            """, (session_id,))
+            """,
+                (session_id,),
+            )
             conn.commit()
 
     def clear_all(self) -> None: