Bound self-update archive extraction

[ryanfowler]

Summary

• Add shared extraction limits for self-update archives with cumulative decompressed byte and entry-count caps.
• Route tar.gz and zip unpacking through bounded copy helpers and remove partial outputs on limit failures.
• Add regression tests for tar.gz and zip archives that exceed a small extraction limit.

Testing

• cargo fmt
• cargo clippy --locked --all-targets --all-features -- -D warnings
• cargo test --all-features test_unpack
• cargo test --all-features