Fix clippy recipe to fail on warnings

[nanookclaw]

Closes #106.

This keeps the existing cargo clippy --fix pass, then runs clippy again without --fix. That second pass preserves the -Dwarnings exit behavior, so lint-heavy fails when warnings remain instead of accepting them after cargo fix.

Running the stricter pass exposed existing Python binding error-shape lints. I marked the few rich error-returning methods with the same local allow style already used for type complexity, adding result_large_err where needed. Cargo also refreshed the two local package versions in Cargo.lock from 0.35.1 to 0.35.2 to match Cargo.toml.

Verification:

• just --show clippy
• just --dry-run clippy
• cargo fmt --check
• cargo clippy --no-deps -- -Dwarnings
• just clippy

I also ran just lint-heavy; clippy passed, then mypy stopped on missing local Python dependencies/stubs (cbor2, multiprocess, opentelemetry exporter) before code-specific type errors.