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/.github/workflows/ci.yml

@@ -0,0 +1,136 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  check:
+    name: Check (${{ matrix.os }}, rust ${{ matrix.rust }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-2025]
+        rust: ["1.85", stable]
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+          components: rustfmt, clippy
+
+      - name: Cache cargo registry and target
+        uses: Swatinem/rust-cache@v2
+
+      - name: Check formatting
+        run: cargo fmt --check
+
+      - name: Run clippy lints
+        run: cargo clippy --all-targets -- -D warnings
+
+      - name: Run tests
+        run: cargo test
+
+      - name: Build documentation
+        run: cargo doc --no-deps
+
+  docker-tests:
+    name: Docker integration tests
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Cache cargo registry and target
+        uses: Swatinem/rust-cache@v2
+
+      - name: Start SMB containers
+        run: ./tests/docker/start.sh internal
+
+      - name: Run Docker integration tests
+        run: cargo test --test docker_integration -- --ignored
+        env:
+          RUST_LOG: smb2=info
+
+      - name: Stop containers
+        if: always()
+        run: ./tests/docker/stop.sh
+
+  consumer-tests:
+    name: Consumer integration tests
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Cache cargo registry and target
+        uses: Swatinem/rust-cache@v2
+
+      - name: Start consumer containers
+        run: ./tests/docker/start.sh consumer
+
+      - name: Run consumer integration tests
+        run: cargo test --features testing --test consumer_integration -- --ignored
+        env:
+          RUST_LOG: smb2=info
+
+      - name: Stop containers
+        if: always()
+        run: ./tests/docker/stop.sh
+
+  msrv:
+    name: Verify MSRV (1.85)
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - name: Install Rust toolchain (MSRV)
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: "1.85"
+
+      - name: Cache cargo registry and target
+        uses: Swatinem/rust-cache@v2
+
+      - name: Check compilation on MSRV
+        run: cargo check
+        env:
+          RUSTFLAGS: "-D warnings"
+
+  ci-ok:
+    name: CI OK
+    runs-on: ubuntu-latest
+    needs: [check, docker-tests, consumer-tests, msrv]
+    if: always()
+    steps:
+      - name: Check all jobs passed
+        run: |
+          if [[ "${{ contains(needs.*.result, 'failure') }}" == "true" ]]; then
+            echo "Some jobs failed"
+            exit 1
+          fi
+          if [[ "${{ contains(needs.*.result, 'cancelled') }}" == "true" ]]; then
+            echo "Some jobs were cancelled"
+            exit 1
+          fi
+          echo "All jobs passed"