ci(lint): Add managed feature check to CI

The managed feature flag was only tested during Docker image builds,
which run late in the release pipeline. Add `cargo check --features
managed` to the Linux lint job so breakage is caught on every PR.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: runningcode

.github/workflows/lint.yml

@@ -89,3 +89,7 @@ jobs:
 
       - name: Run Clippy
         run: cargo clippy --workspace --tests --target ${{ matrix.target }}
+
+      - name: Check managed feature compiles
+        if: matrix.target == 'x86_64-unknown-linux-musl'
+        run: cargo check --features managed --target ${{ matrix.target }}