SMB Server Phase 2: VFS backend build fix + integration test

- Add VfsFile: Send supertrait for Mutex compatibility
- Fix SmbServerCommand: struct → Subcommand enum with Start variant
- Fix tracing_subscriber::init() → try_init() to avoid panic when
  logger already initialized
- Fix CLI subcommand name: smb-server → smb-start (flatten naming)
- Add #[command(name = "smb-start")] for CLI disambiguation
- Fix unused variable warnings (smb_fs.rs, smb_server_backend.rs)
- Remove unused VfsFile imports (webdav.rs, scp_handler.rs)
- Integration test: Docker smbclient verified (list, upload, read)

vendor/smb2/.codegraph/config.json

@@ -0,0 +1,140 @@
+{
+  "version": 1,
+  "include": [
+    "**/*.ts",
+    "**/*.tsx",
+    "**/*.js",
+    "**/*.jsx",
+    "**/*.py",
+    "**/*.go",
+    "**/*.rs",
+    "**/*.java",
+    "**/*.c",
+    "**/*.h",
+    "**/*.cpp",
+    "**/*.hpp",
+    "**/*.cc",
+    "**/*.cxx",
+    "**/*.cs",
+    "**/*.php",
+    "**/*.rb",
+    "**/*.swift",
+    "**/*.kt",
+    "**/*.kts",
+    "**/*.dart",
+    "**/*.svelte",
+    "**/*.liquid",
+    "**/*.pas",
+    "**/*.dpr",
+    "**/*.dpk",
+    "**/*.lpr",
+    "**/*.dfm",
+    "**/*.fmx"
+  ],
+  "exclude": [
+    "**/.git/**",
+    "**/node_modules/**",
+    "**/vendor/**",
+    "**/Pods/**",
+    "**/dist/**",
+    "**/build/**",
+    "**/out/**",
+    "**/bin/**",
+    "**/obj/**",
+    "**/target/**",
+    "**/*.min.js",
+    "**/*.bundle.js",
+    "**/.next/**",
+    "**/.nuxt/**",
+    "**/.svelte-kit/**",
+    "**/.output/**",
+    "**/.turbo/**",
+    "**/.cache/**",
+    "**/.parcel-cache/**",
+    "**/.vite/**",
+    "**/.astro/**",
+    "**/.docusaurus/**",
+    "**/.gatsby/**",
+    "**/.webpack/**",
+    "**/.nx/**",
+    "**/.yarn/cache/**",
+    "**/.pnpm-store/**",
+    "**/storybook-static/**",
+    "**/.expo/**",
+    "**/web-build/**",
+    "**/ios/Pods/**",
+    "**/ios/build/**",
+    "**/android/build/**",
+    "**/android/.gradle/**",
+    "**/__pycache__/**",
+    "**/.venv/**",
+    "**/venv/**",
+    "**/site-packages/**",
+    "**/dist-packages/**",
+    "**/.pytest_cache/**",
+    "**/.mypy_cache/**",
+    "**/.ruff_cache/**",
+    "**/.tox/**",
+    "**/.nox/**",
+    "**/*.egg-info/**",
+    "**/.eggs/**",
+    "**/go/pkg/mod/**",
+    "**/target/debug/**",
+    "**/target/release/**",
+    "**/.gradle/**",
+    "**/.m2/**",
+    "**/generated-sources/**",
+    "**/.kotlin/**",
+    "**/.dart_tool/**",
+    "**/.vs/**",
+    "**/.nuget/**",
+    "**/artifacts/**",
+    "**/publish/**",
+    "**/cmake-build-*/**",
+    "**/CMakeFiles/**",
+    "**/bazel-*/**",
+    "**/vcpkg_installed/**",
+    "**/.conan/**",
+    "**/Debug/**",
+    "**/Release/**",
+    "**/x64/**",
+    "**/.pio/**",
+    "**/release/**",
+    "**/*.app/**",
+    "**/*.asar",
+    "**/DerivedData/**",
+    "**/.build/**",
+    "**/.swiftpm/**",
+    "**/xcuserdata/**",
+    "**/Carthage/Build/**",
+    "**/SourcePackages/**",
+    "**/__history/**",
+    "**/__recovery/**",
+    "**/*.dcu",
+    "**/.composer/**",
+    "**/storage/framework/**",
+    "**/bootstrap/cache/**",
+    "**/.bundle/**",
+    "**/tmp/cache/**",
+    "**/public/assets/**",
+    "**/public/packs/**",
+    "**/.yardoc/**",
+    "**/coverage/**",
+    "**/htmlcov/**",
+    "**/.nyc_output/**",
+    "**/test-results/**",
+    "**/.coverage/**",
+    "**/.idea/**",
+    "**/logs/**",
+    "**/tmp/**",
+    "**/temp/**",
+    "**/_build/**",
+    "**/docs/_build/**",
+    "**/site/**"
+  ],
+  "languages": [],
+  "frameworks": [],
+  "maxFileSize": 1048576,
+  "extractDocstrings": true,
+  "trackCallSites": true
+}