Optimize DAG-CBOR encode by reusing a thread-local buffer and validating CIDs without Multihash construction

[MarshalX]

No description provided.

[codspeed-hq]

Merging this PR will improve performance by 21.69%

⚡ 5 improved benchmarks
✅ 195 untouched benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	test_dag_cbor_decode_torture_cids	34.4 ms	26.7 ms	+28.71%
⚡	Simulation	test_encode[github-libipld]	478.4 µs	385.1 µs	+24.21%
⚡	Simulation	test_dag_cbor_encode_real_data[github.json]	457.8 µs	368.9 µs	+24.1%
⚡	Simulation	test_encode[twitter-libipld]	4 ms	3.4 ms	+15.98%
⚡	Simulation	test_dag_cbor_encode_real_data[twitter.json]	4 ms	3.4 ms	+15.96%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing optimize-encode-buffer-reuse-and-cid-parse (1995d1a) with main (7970600)}