## Summary

Fixes the 5 remaining virtual-dsm test failures identified in the #22
handoff, bringing vdsm from 42/47 to **47/47 passing**. Includes two
production code improvements that benefit real users.

### Production code changes

1. **`get_dir_size` handles error 599 gracefully**
(`src/mcp_synology/modules/filestation/metadata.py`)
- On Virtual DSM (and potentially real NAS with tiny directories), the
DirSize background task can complete and be cleaned up before the first
status poll
- Previously crashed with an unhandled SynologyError; now returns a
best-effort "completed (too fast to measure)" result
   - New unit test covers this path

2. **`list_recycle_bin` handles error 408 on `#recycle` path**
(`src/mcp_synology/modules/filestation/listing.py`)
- When recycle bin is disabled on a share, the `#recycle` directory
doesn't exist and DSM returns error 408
- Previously raised ToolError; now returns a friendly "Recycle bin is
not enabled" message
- Added `json` and `ToolError` imports, plus `logger` for debug tracing

### Test changes

| Test | Root Cause | Fix |
|------|-----------|-----|
| `test_get_system_info` | VirtualDSM has no temp sensor | Temperature
assertion conditional on `"VirtualDSM" not in result` |
| `test_get_dir_size` | Error 599 — task gone before poll | Fixed in
production code (see above); test passes with best-effort result |
| `test_02_list_recycle_bin` | Recycle bin disabled on vdsm shares |
Fixed in production code (see above) + enabled in setup |
| `test_search_keyword_finds_directory` | DSM search matches names not
content; search service overloaded | Creates "Bambu Studio" dir via API;
searches from share root; retries with delays |
| `test_utilization_before_and_during_load` | DirSize load generator
fails on vdsm | Wrapped `await dir_task` in try/except (it's just a load
generator) |

### Setup changes

- `tests/vdsm/setup_dsm.py`: Enables recycle bin via `synoshare --setopt
<share> enable_recycle_bin=yes` after share creation
- `tests/vdsm/setup_dsm.py`: Creates "Bambu Studio" directory (name
match for search) instead of only `search_target.txt` (content match —
DSM search doesn't search content)

### Files changed

- `src/mcp_synology/modules/filestation/metadata.py` — error 599
handling in DirSize poll loop
- `src/mcp_synology/modules/filestation/listing.py` — error 408 handling
in `list_recycle_bin`
- `tests/test_integration.py` — all 5 test fixes
- `tests/modules/filestation/test_metadata.py` — new unit test
`test_dir_size_error_599_instant_completion`
- `tests/vdsm/setup_dsm.py` — recycle bin enablement + Bambu Studio
directory
- `CHANGELOG.md` — Unreleased entry

## Test plan

### Automated (CI)
- [x] Unit tests pass: `uv run pytest` (491 tests, 96% coverage,
`--cov-fail-under=95` enforced)
- [x] Ruff lint + format clean
- [x] mypy strict passes
- [x] Codecov patch coverage acceptable

### Manual — vdsm integration tests

**Prerequisites:**
- Linux with KVM support (`/dev/kvm` must exist)
- Podman with user socket enabled: `systemctl --user enable --now
podman.socket`
- Golden image at `.vdsm/golden/dsm-7.2.2.tar.gz` — build with:
  ```bash
echo y | uv run python scripts/vdsm_setup.py --version 7.2.2
--admin-user mcpadmin --admin-password 'McpTest123!'
  ```
**Note:** The golden image from #22 works for 46/47 tests. For the
search test, the fix creates the "Bambu Studio" directory via the
FileStation API at test time, so a rebuild is not required. However,
rebuilding with the updated `setup_dsm.py` will also enable recycle bin
in the image and create the directory at golden image time.

**Run the full vdsm suite:**
```bash
uv run pytest -m vdsm -v --no-cov --log-cli-level=INFO
```

**Expected:** 47/47 PASSED (container boot ~30s, full suite ~4-5
minutes)

**Verify each of the 5 previously-failing tests:**
- [ ] `TestSystemInfo::test_get_system_info` — PASSED (no Temperature
assertion on VirtualDSM)
- [ ] `TestMetadata::test_get_dir_size` — PASSED (logs "completed (too
fast to measure)")
- [ ] `TestRecycleBin::test_02_list_recycle_bin` — PASSED (returns "not
enabled" message gracefully)
- [ ] `TestSearch::test_search_keyword_finds_directory` — PASSED
(creates dir, finds on first attempt from share root)
- [ ] `TestResourceUsage::test_utilization_before_and_during_load` —
PASSED (tolerates DirSize failure)

**Check the log output for the production code paths:**
- [ ] DirSize log shows: `Directory Size: /writable ... Total size:
completed (too fast to measure)`
- [ ] Recycle bin log shows: `Recycle bin is not enabled on /writable.
Deleted files cannot be recovered.`
- [ ] Search log shows: `Created search target directory:
/testshare/Documents/Bambu Studio` then `1 results found`

### Regression — real NAS integration tests (optional)
If `tests/integration_config.yaml` is configured:
```bash
uv run pytest -m integration -v --log-cli-level=INFO
```
The test changes are backward-compatible:
- Temperature assertion still enforced on physical hardware
(`"VirtualDSM" not in result`)
- Search target creation is non-fatal if the folder is read-only
- DirSize error 599 is unlikely on real NAS but handled gracefully if it
occurs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: cmeans-claude-dev[bot] <3223881+cmeans-claude-dev[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>