v0.6.7

Added

• Code coverage reports in CI: A new coverage job runs on every push and pull request using cargo-llvm-cov. The HTML coverage report is uploaded as a coverage-report GitHub Actions artifact and LCOV data is uploaded to Codecov. See the Code Coverage section in the copilot instructions for how to generate reports locally.

Fixed

• Website becomes unresponsive during index building: API handlers (search, stats, dependents, dependencies, diagnostics) previously called engine.read() which blocks until any pending write lock (held during batch merges) is released. Under concurrent load, this caused blocking threads to pile up and exhaust the Tokio thread pool, leading to memory pressure and system unresponsiveness. All handlers now use engine.try_read() and immediately return 503 Service Unavailable with the message "Index is currently being updated, please try again shortly" when the write lock is held. The status endpoint was already safe and is unchanged.