test(tui): add TDD failing test for SQLite session persistence

Add BDD scenarios that capture bug #4739 — the missing TUI SQLite
session persistence layer. The cleveragents.tui.session_store module
and TuiSessionStore class do not exist; these tests verify their
absence and will pass once the implementation is in place.

All scenarios are tagged @tdd_expected_fail so CI passes while the
module is absent. The expected-fail mechanism inverts the result:
a failing AssertionError means the bug still exists (CI passes).

ISSUES CLOSED: #10879

features/steps/tdd_tui_session_store_4739_steps.py

@@ -0,0 +1,154 @@
+"""Step definitions for TDD Bug #4739 — TUI SQLite session persistence not implemented.
+
+These steps verify that ``cleveragents.tui.session_store`` exists and that
+``TuiSessionStore`` can persist and retrieve session records from SQLite.
+
+All scenarios are tagged ``@tdd_expected_fail`` so CI passes while the
+module is absent.  The expected-fail mechanism inverts the result: a
+failing assertion means the bug is still present (CI passes); a passing
+assertion means the fix has been applied (CI also passes after the
+``@tdd_expected_fail`` tag is removed in the bugfix PR).
+
+Failure mode: ``AssertionError`` (not ``ImportError`` or ``RuntimeError``).
+"""
+
+from __future__ import annotations
+
+import importlib
+import os
+import shutil
+import tempfile
+import types
+
+from behave import given, then, when
+from behave.runner import Context
+
+
+@given("the tdd4739 test environment is set up")
+def step_tdd4739_setup(context: Context) -> None:
+    """Initialise context attributes used across tdd4739 steps."""
+    context.tdd4739_module: types.ModuleType | None = None
+    context.tdd4739_import_error: Exception | None = None
+    context.tdd4739_store: object | None = None
+    context.tdd4739_tmpdir: str | None = None
+
+
+@given("the tdd4739 test environment is set up with a temp db path")
+def step_tdd4739_setup_with_tmpdir(context: Context) -> None:
+    """Initialise context and create a temporary directory for the SQLite db."""
+    context.tdd4739_module = None
+    context.tdd4739_import_error = None
+    context.tdd4739_store = None
+
+    tmpdir = tempfile.mkdtemp(prefix="tdd4739_")
+    context.tdd4739_tmpdir = tmpdir
+    context.tdd4739_db_path = os.path.join(tmpdir, "tui.db")
+
+    def _cleanup() -> None:
+        shutil.rmtree(tmpdir, ignore_errors=True)
+
+    context.add_cleanup(_cleanup)
+
+
+@when("I attempt to import cleveragents.tui.session_store")
+def step_tdd4739_import(context: Context) -> None:
+    """Attempt to import the session_store module; capture any ImportError."""
+    try:
+        mod = importlib.import_module("cleveragents.tui.session_store")
+        context.tdd4739_module = mod
+        context.tdd4739_import_error = None
+    except ImportError as exc:
+        context.tdd4739_module = None
+        context.tdd4739_import_error = exc
+
+
+@then("the tdd4739 import should succeed without errors")
+def step_tdd4739_import_ok(context: Context) -> None:
+    """Assert the import succeeded — fails via AssertionError if module is absent."""
+    assert context.tdd4739_import_error is None, (
+        f"cleveragents.tui.session_store could not be imported: "
+        f"{context.tdd4739_import_error}"
+    )
+    assert context.tdd4739_module is not None, (
+        "cleveragents.tui.session_store module is None after import"
+    )
+
+
+@then("the tdd4739 module should expose a TuiSessionStore class")
+def step_tdd4739_class_exists(context: Context) -> None:
+    """Assert TuiSessionStore is present in the module."""
+    assert context.tdd4739_import_error is None, (
+        f"cleveragents.tui.session_store could not be imported: "
+        f"{context.tdd4739_import_error}"
+    )
+    mod = context.tdd4739_module
+    assert mod is not None, "session_store module is None"
+    assert hasattr(mod, "TuiSessionStore"), (
+        "cleveragents.tui.session_store does not expose a TuiSessionStore class"
+    )
+
+
+@when("I create a TuiSessionStore pointing at the temp db path")
+def step_tdd4739_create_store(context: Context) -> None:
+    """Instantiate TuiSessionStore with the temp db path."""
+    try:
+        mod = importlib.import_module("cleveragents.tui.session_store")
+    except ImportError as exc:
+        raise AssertionError(
+            f"cleveragents.tui.session_store could not be imported: {exc}"
+        ) from exc
+
+    assert hasattr(mod, "TuiSessionStore"), (
+        "cleveragents.tui.session_store does not expose a TuiSessionStore class"
+    )
+    context.tdd4739_store = mod.TuiSessionStore(db_path=context.tdd4739_db_path)
+
+
+@when('I save a tdd4739 session record with id "{session_id}"')
+def step_tdd4739_save_session(context: Context, session_id: str) -> None:
+    """Save a minimal session record to the store."""
+    store = context.tdd4739_store
+    assert store is not None, "TuiSessionStore was not created"
+    store.save(  # type: ignore[union-attr]
+        session_id=session_id,
+        persona_name="default",
+        actor_identity="anthropic/claude-4-sonnet",
+        title=f"Test session {session_id}",
+        prompt_count=0,
+        total_cost=0.0,
+        created_at="2026-01-01T00:00:00Z",
+        last_used="2026-01-01T00:00:00Z",
+        project_path=None,
+        meta_json="{}",
+    )
+
+
+@then('the tdd4739 session record should be retrievable by id "{session_id}"')
+def step_tdd4739_get_session(context: Context, session_id: str) -> None:
+    """Assert the session record can be retrieved by its id."""
+    store = context.tdd4739_store
+    assert store is not None, "TuiSessionStore was not created"
+    record = store.get(session_id)  # type: ignore[union-attr]
+    assert record is not None, (
+        f"TuiSessionStore.get('{session_id}') returned None — "
+        f"session was not persisted"
+    )
+    assert getattr(record, "id", None) == session_id or (
+        isinstance(record, dict) and record.get("id") == session_id
+    ), (
+        f"Retrieved record id mismatch: expected '{session_id}', "
+        f"got {getattr(record, 'id', record)!r}"
+    )
+
+
+@then("the tdd4739 session store should list {count:d} sessions")
+def step_tdd4739_list_sessions(context: Context, count: int) -> None:
+    """Assert the store lists the expected number of sessions."""
+    store = context.tdd4739_store
+    assert store is not None, "TuiSessionStore was not created"
+    sessions = store.list_all()  # type: ignore[union-attr]
+    assert sessions is not None, "TuiSessionStore.list_all() returned None"
+    actual = len(sessions)
+    assert actual == count, (
+        f"Expected {count} sessions in store, got {actual}"
+    )

features/tdd_tui_session_store_4739.feature

@@ -0,0 +1,39 @@
+@tdd_issue @tdd_issue_4739
+Feature: Bug #4739 — TUI SQLite session persistence not implemented
+  As a developer
+  I want to verify that the TUI session persistence layer exists
+  So that the bug is captured and will be caught by a regression test
+
+  The spec (§Session Persistence and Resume) requires TUI sessions to be
+  persisted in an SQLite database at ~/.local/state/cleveragents/tui.db
+  via a TuiSessionStore class in cleveragents.tui.session_store.
+
+  Currently no such module exists — the TUI hardcodes a single in-memory
+  session and has no SQLite persistence layer.
+
+  @tdd_issue @tdd_issue_4739 @tdd_expected_fail
+  Scenario: TuiSessionStore module can be imported from cleveragents.tui
+    Given the tdd4739 test environment is set up
+    When I attempt to import cleveragents.tui.session_store
+    Then the tdd4739 import should succeed without errors
+
+  @tdd_issue @tdd_issue_4739 @tdd_expected_fail
+  Scenario: TuiSessionStore class exists in the session_store module
+    Given the tdd4739 test environment is set up
+    When I attempt to import cleveragents.tui.session_store
+    Then the tdd4739 module should expose a TuiSessionStore class
+
+  @tdd_issue @tdd_issue_4739 @tdd_expected_fail
+  Scenario: TuiSessionStore can persist a session record to SQLite
+    Given the tdd4739 test environment is set up with a temp db path
+    When I create a TuiSessionStore pointing at the temp db path
+    And I save a tdd4739 session record with id "test-session-001"
+    Then the tdd4739 session record should be retrievable by id "test-session-001"
+
+  @tdd_issue @tdd_issue_4739 @tdd_expected_fail
+  Scenario: TuiSessionStore lists all persisted sessions
+    Given the tdd4739 test environment is set up with a temp db path
+    When I create a TuiSessionStore pointing at the temp db path
+    And I save a tdd4739 session record with id "sess-a"
+    And I save a tdd4739 session record with id "sess-b"
+    Then the tdd4739 session store should list 2 sessions