Use strict IP pipeline sorting

[terjekv]

Closes #57

• replace permissive dotted-byte ordering with the shared strict IpAddr cast
• preserve numeric IPv4/IPv6 ordering and address-family semantics across multi-key and fanout sorts
• cover errors, renderers, redirects, completion, help, and crate documentation

Verification:

• cargo test --workspace
• cargo clippy --all-targets -- -D warnings
• cargo fmt --all -- --check
• git ls-files -z '*.md' | xargs -0 npx --yes markdownlint-cli2@0.23.2 --config .markdownlint.json