Remove the pre-1.0 Python implementation, its test suite, packaging file, and development commands. The repository now contains only the Rust-native observer. Move the pinned D-Bus Observer1 introspection fixture into the Rust crate so its wire-contract conformance check retains an authoritative input. Drop the test that hashed the old Python service-unit template without comparing it to the native template. Update the documentation to describe only the native implementation. Previously published PyPI versions remain available; nothing is unpublished.