Enable clippy::clone_on_ref_ptr lint and fix all violations

[joseph-isaacs]

Summary

• Adds clone_on_ref_ptr = "deny" to [workspace.lints.clippy] in the root Cargo.toml
• Fixes all ~450 violations across 126 files by replacing x.clone() on Arc/Rc/Weak with explicit Arc::clone(&x) (or turbofish Arc::<T>::clone(&x) where type coercion is needed)
• No #[allow] suppressions anywhere

This makes ref-count bumps visually distinct from deep clones, improving code readability.

Test plan

• cargo clippy --all-targets --all-features passes with zero errors/warnings
• cargo +nightly fmt --all applied
• cargo xtask public-api regenerated
• No #[allow(clippy::clone_on_ref_ptr)] anywhere in the codebase

🤖 Generated with Claude Code

[codspeed-hq]

Merging this PR will improve performance by 20.72%

⚡ 1 improved benchmark
✅ 1121 untouched benchmarks
⏩ 1530 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	chunked_bool_canonical_into[(1000, 10)]	60.2 µs	49.9 µs	+20.72%

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_{Comparing joseph-isaacs:ji/lint-clone-on-ref-ptr-v2 (5b00928) with develop (bbb371c)}

Footnotes

1. 1530 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩