test(box): cover inbound/outbound attachment helpers; fix ruff format

- ruff format localagent.py (CI ruff format --check was failing)
- add unit tests for ResponseWrapper outbound-attachment helpers (wrapper.py 78%->98%)
- add unit tests for LocalAgentRunner._inject_inbound_attachments
- add unit tests for WebSocketAdapter._process_image_components (0%->covered)

Lifts PR patch coverage from 68.97% to ~88% (>75% target).

tests/unit_tests/platform/test_websocket_adapter_attachments.py

@@ -0,0 +1,92 @@
+"""Unit tests for WebSocketAdapter._process_image_components.
+
+The web debug client uploads Image / Voice / File components carrying a storage
+key in ``path``. This helper resolves each to a base64 data URI (so multimodal
+LLM input and the Box sandbox inbox have usable bytes), then deletes the
+consumed storage object and clears ``path``. Covers mimetype selection per
+type and graceful error handling.
+"""
+
+from __future__ import annotations
+
+import base64
+from unittest.mock import AsyncMock, Mock
+
+import pytest
+
+from langbot.pkg.platform.sources.websocket_adapter import WebSocketAdapter
+
+
+def _make_adapter(load_return=b'hello', load_side_effect=None):
+    provider = Mock()
+    provider.load = AsyncMock(return_value=load_return, side_effect=load_side_effect)
+    provider.delete = AsyncMock()
+    ap = Mock()
+    ap.storage_mgr.storage_provider = provider
+    logger = Mock()
+    logger.error = AsyncMock()
+    # WebSocketAdapter is a pydantic model; bypass full __init__/validation.
+    adapter = WebSocketAdapter.model_construct(ap=ap, logger=logger)
+    return adapter, provider
+
+
+@pytest.mark.asyncio
+async def test_image_jpeg_mimetype_and_cleanup():
+    adapter, provider = _make_adapter(load_return=b'\xff\xd8\xff')
+    chain = [{'type': 'Image', 'path': 'storage://abc/photo.jpg'}]
+
+    await adapter._process_image_components(chain)
+
+    expected_b64 = base64.b64encode(b'\xff\xd8\xff').decode('utf-8')
+    assert chain[0]['base64'] == f'data:image/jpeg;base64,{expected_b64}'
+    assert chain[0]['path'] == ''  # consumed
+    provider.delete.assert_awaited_once_with('storage://abc/photo.jpg')
+
+
+@pytest.mark.asyncio
+async def test_image_defaults_to_png():
+    adapter, _ = _make_adapter()
+    chain = [{'type': 'Image', 'path': 'storage://abc/blob'}]
+    await adapter._process_image_components(chain)
+    assert chain[0]['base64'].startswith('data:image/png;base64,')
+
+
+@pytest.mark.asyncio
+async def test_voice_uses_guessed_or_wav_mimetype():
+    adapter, _ = _make_adapter()
+    chain = [{'type': 'Voice', 'path': 'storage://abc/clip.wav'}]
+    await adapter._process_image_components(chain)
+    assert chain[0]['base64'].startswith('data:audio/')
+
+
+@pytest.mark.asyncio
+async def test_file_uses_octet_stream_fallback():
+    adapter, _ = _make_adapter()
+    chain = [{'type': 'File', 'path': 'storage://abc/unknownblob'}]
+    await adapter._process_image_components(chain)
+    assert chain[0]['base64'].startswith('data:application/octet-stream;base64,')
+
+
+@pytest.mark.asyncio
+async def test_skips_components_without_path_or_unknown_type():
+    adapter, provider = _make_adapter()
+    chain = [
+        {'type': 'Image', 'path': ''},  # no path
+        {'type': 'Plain', 'path': 'storage://abc/x'},  # not a file component
+        {'type': 'At', 'target': '123'},  # no path key at all
+    ]
+    await adapter._process_image_components(chain)
+    provider.load.assert_not_awaited()
+    assert 'base64' not in chain[0]
+    assert 'base64' not in chain[1]
+
+
+@pytest.mark.asyncio
+async def test_load_failure_is_logged_not_raised():
+    adapter, _ = _make_adapter(load_side_effect=RuntimeError('storage down'))
+    chain = [{'type': 'File', 'path': 'storage://abc/doc.pdf'}]
+
+    # must not raise
+    await adapter._process_image_components(chain)
+    assert 'base64' not in chain[0]
+    adapter.logger.error.assert_awaited_once()