94e5aec4af
- Extract the WebDAV/REST mount-download Range decision (parse + validate + satisfiable) into a pure `plan_mount_range`, unit-tested across no-range, malformed, inclusive, open-ended, suffix, and out-of-bounds cases. This was the one untested branch of `download_mount_file` (its I/O deps are already integration-covered). - Add `just coverage [filter]` and `just coverage-integration [filter]` recipes wrapping cargo-llvm-cov (HTML + summary; integration variant adds the testcontainers tests).