feat(#160): wire claw list-sessions and delete-session CLI commands

Closes the last #160 gap: claws can now manage session lifecycle entirely
through the CLI without filesystem hacks.

New commands:
- claw list-sessions [--directory DIR] [--output-format text|json]
  Enumerates stored session IDs. JSON mode emits {sessions, count}.
  Missing/empty directories return empty list (exit 0), not an error.

- claw delete-session SESSION_ID [--directory DIR] [--output-format text|json]
  Idempotent: not-found is exit 0 with status='not_found' (no raise).
  Partial-failure: exit 1 with typed JSON error envelope:
    {session_id, deleted: false, error: {kind, message, retryable}}
  The 'session_delete_failed' kind is retryable=true so orchestrators
  know to retry vs escalate.

Public API surface extended in src/__init__.py:
- list_sessions, session_exists, delete_session
- SessionNotFoundError, SessionDeleteError

Tests added (tests/test_porting_workspace.py):
- test_list_sessions_cli_runs: text + json modes against tempdir
- test_delete_session_cli_idempotent: first call deleted=true,
  second call deleted=false (exit 0, status=not_found)
- test_delete_session_cli_partial_failure_exit_1: permission error
  surfaces as exit 1 + typed JSON error with retryable=true

All 43 tests pass. The session storage abstraction chapter is closed:
- storage layer decoupled from claw code (#160 initial impl)
- delete contract hardened + caller-audited (#160 hardening pass)
- CLI wired with idempotency preserved at exit-code boundary (this commit)

src/__init__.py

@@ -5,7 +5,16 @@ from .parity_audit import ParityAuditResult, run_parity_audit
 from .port_manifest import PortManifest, build_port_manifest
 from .query_engine import QueryEnginePort, TurnResult
 from .runtime import PortRuntime, RuntimeSession
-from .session_store import StoredSession, load_session, save_session
+from .session_store import (
+    SessionDeleteError,
+    SessionNotFoundError,
+    StoredSession,
+    delete_session,
+    list_sessions,
+    load_session,
+    save_session,
+    session_exists,
+)
 from .system_init import build_system_init_message
 from .tools import PORTED_TOOLS, build_tool_backlog
 
@@ -15,6 +24,8 @@ __all__ = [
     'PortRuntime',
     'QueryEnginePort',
     'RuntimeSession',
+    'SessionDeleteError',
+    'SessionNotFoundError',
     'StoredSession',
     'TurnResult',
     'PORTED_COMMANDS',
@@ -23,7 +34,10 @@ __all__ = [
     'build_port_manifest',
     'build_system_init_message',
     'build_tool_backlog',
+    'delete_session',
+    'list_sessions',
     'load_session',
     'run_parity_audit',
     'save_session',
+    'session_exists',
 ]

src/main.py

@@ -12,7 +12,14 @@ from .port_manifest import build_port_manifest
 from .query_engine import QueryEnginePort
 from .remote_runtime import run_remote_mode, run_ssh_mode, run_teleport_mode
 from .runtime import PortRuntime
-from .session_store import load_session
+from .session_store import (
+    SessionDeleteError,
+    SessionNotFoundError,
+    delete_session,
+    list_sessions,
+    load_session,
+    session_exists,
+)
 from .setup import run_setup
 from .tool_pool import assemble_tool_pool
 from .tools import execute_tool, get_tool, get_tools, render_tool_index
@@ -65,6 +72,35 @@ def build_parser() -> argparse.ArgumentParser:
     load_session_parser = subparsers.add_parser('load-session', help='load a previously persisted session')
     load_session_parser.add_argument('session_id')
 
+    list_sessions_parser = subparsers.add_parser(
+        'list-sessions',
+        help='enumerate stored session IDs (#160: claw-native session API)',
+    )
+    list_sessions_parser.add_argument(
+        '--directory', help='session storage directory (default: .port_sessions)'
+    )
+    list_sessions_parser.add_argument(
+        '--output-format',
+        choices=['text', 'json'],
+        default='text',
+        help='output format',
+    )
+
+    delete_session_parser = subparsers.add_parser(
+        'delete-session',
+        help='delete a persisted session (#160: idempotent, race-safe)',
+    )
+    delete_session_parser.add_argument('session_id')
+    delete_session_parser.add_argument(
+        '--directory', help='session storage directory (default: .port_sessions)'
+    )
+    delete_session_parser.add_argument(
+        '--output-format',
+        choices=['text', 'json'],
+        default='text',
+        help='output format',
+    )
+
     remote_parser = subparsers.add_parser('remote-mode', help='simulate remote-control runtime branching')
     remote_parser.add_argument('target')
     ssh_parser = subparsers.add_parser('ssh-mode', help='simulate SSH runtime branching')
@@ -168,6 +204,55 @@ def main(argv: list[str] | None = None) -> int:
         session = load_session(args.session_id)
         print(f'{session.session_id}\n{len(session.messages)} messages\nin={session.input_tokens} out={session.output_tokens}')
         return 0
+    if args.command == 'list-sessions':
+        from pathlib import Path as _Path
+        directory = _Path(args.directory) if args.directory else None
+        ids = list_sessions(directory)
+        if args.output_format == 'json':
+            import json as _json
+            print(_json.dumps({'sessions': ids, 'count': len(ids)}))
+        else:
+            if not ids:
+                print('(no sessions)')
+            else:
+                for sid in ids:
+                    print(sid)
+        return 0
+    if args.command == 'delete-session':
+        from pathlib import Path as _Path
+        directory = _Path(args.directory) if args.directory else None
+        try:
+            deleted = delete_session(args.session_id, directory)
+        except SessionDeleteError as exc:
+            if args.output_format == 'json':
+                import json as _json
+                print(_json.dumps({
+                    'session_id': args.session_id,
+                    'deleted': False,
+                    'error': {
+                        'kind': 'session_delete_failed',
+                        'message': str(exc),
+                        'retryable': True,
+                    },
+                }))
+            else:
+                print(f'error: {exc}')
+            return 1
+        if args.output_format == 'json':
+            import json as _json
+            print(_json.dumps({
+                'session_id': args.session_id,
+                'deleted': deleted,
+                'status': 'deleted' if deleted else 'not_found',
+            }))
+        else:
+            if deleted:
+                print(f'deleted: {args.session_id}')
+            else:
+                print(f'not found: {args.session_id}')
+        # Exit 0 for both cases — delete_session is idempotent,
+        # not-found is success from a cleanup perspective
+        return 0
     if args.command == 'remote-mode':
         print(run_remote_mode(args.target).as_text())
         return 0

tests/test_porting_workspace.py

@@ -173,6 +173,93 @@ class PortingWorkspaceTests(unittest.TestCase):
         self.assertIn(session_id, result.stdout)
         self.assertIn('messages', result.stdout)
 
+    def test_list_sessions_cli_runs(self) -> None:
+        """#160: list-sessions CLI enumerates stored sessions in text + json."""
+        import json
+        import tempfile
+        from src.session_store import StoredSession, save_session
+
+        with tempfile.TemporaryDirectory() as tmp:
+            tmp_path = Path(tmp)
+            for sid in ['alpha', 'bravo']:
+                save_session(
+                    StoredSession(session_id=sid, messages=('hi',), input_tokens=1, output_tokens=2),
+                    tmp_path,
+                )
+            # text mode
+            text_result = subprocess.run(
+                [sys.executable, '-m', 'src.main', 'list-sessions', '--directory', str(tmp_path)],
+                check=True, capture_output=True, text=True,
+            )
+            self.assertIn('alpha', text_result.stdout)
+            self.assertIn('bravo', text_result.stdout)
+            # json mode
+            json_result = subprocess.run(
+                [sys.executable, '-m', 'src.main', 'list-sessions',
+                 '--directory', str(tmp_path), '--output-format', 'json'],
+                check=True, capture_output=True, text=True,
+            )
+            data = json.loads(json_result.stdout)
+            self.assertEqual(data, {'sessions': ['alpha', 'bravo'], 'count': 2})
+
+    def test_delete_session_cli_idempotent(self) -> None:
+        """#160: delete-session CLI is idempotent (not-found is exit 0, status=not_found)."""
+        import json
+        import tempfile
+        from src.session_store import StoredSession, save_session
+
+        with tempfile.TemporaryDirectory() as tmp:
+            tmp_path = Path(tmp)
+            save_session(
+                StoredSession(session_id='once', messages=('hi',), input_tokens=1, output_tokens=2),
+                tmp_path,
+            )
+            # first delete: success
+            first = subprocess.run(
+                [sys.executable, '-m', 'src.main', 'delete-session', 'once',
+                 '--directory', str(tmp_path), '--output-format', 'json'],
+                capture_output=True, text=True,
+            )
+            self.assertEqual(first.returncode, 0)
+            self.assertEqual(
+                json.loads(first.stdout),
+                {'session_id': 'once', 'deleted': True, 'status': 'deleted'},
+            )
+            # second delete: idempotent, still exit 0
+            second = subprocess.run(
+                [sys.executable, '-m', 'src.main', 'delete-session', 'once',
+                 '--directory', str(tmp_path), '--output-format', 'json'],
+                capture_output=True, text=True,
+            )
+            self.assertEqual(second.returncode, 0)
+            self.assertEqual(
+                json.loads(second.stdout),
+                {'session_id': 'once', 'deleted': False, 'status': 'not_found'},
+            )
+
+    def test_delete_session_cli_partial_failure_exit_1(self) -> None:
+        """#160: partial-failure (permission error) surfaces as exit 1 + typed JSON error."""
+        import json
+        import tempfile
+
+        with tempfile.TemporaryDirectory() as tmp:
+            tmp_path = Path(tmp)
+            bad = tmp_path / 'locked.json'
+            bad.mkdir()
+            try:
+                result = subprocess.run(
+                    [sys.executable, '-m', 'src.main', 'delete-session', 'locked',
+                     '--directory', str(tmp_path), '--output-format', 'json'],
+                    capture_output=True, text=True,
+                )
+                self.assertEqual(result.returncode, 1)
+                data = json.loads(result.stdout)
+                self.assertFalse(data['deleted'])
+                self.assertEqual(data['error']['kind'], 'session_delete_failed')
+                self.assertTrue(data['error']['retryable'])
+            finally:
+                bad.rmdir()
+
     def test_tool_permission_filtering_cli_runs(self) -> None:
         result = subprocess.run(
             [sys.executable, '-m', 'src.main', 'tools', '--limit', '10', '--deny-prefix', 'mcp'],