docs: link OpenChainBench VAA finalization latency benchmark

[Flotapponnier]

Summary

Adds a short subsection under Consistency and Finality in docs/protocol/infrastructure/vaas.md linking to a public, passive observation benchmark of VAA finalization latency by source chain.

The benchmark is computed from the public Wormholescan API (/api/v1/vaas) at 60s poll cadence, records indexedAt - timestamp per VAA as a Prometheus histogram bucketed by emitterChain, and covers roughly 20 source chains. It runs zero canary transactions and issues no writes against Guardian or Wormholescan infrastructure.

• Benchmark: https://openchainbench.com/benchmarks/wormhole-vaa-latency
• Source: https://github.com/ChainBench/openchainbench

Current sample values: Sui ~4-8s, BNB ~5-10s, Polygon ~10-15s, Solana ~15-25s, Ethereum ~15-30s.

Precedent

Similar minimal doc-link contributions previously merged upstream by other chain and protocol projects:

• docs(endpoints): link OpenChainBench public RPC latency benchmark osmosis-labs/docs#349
• docs(latency): link OpenChainBench public Solana DEX quote latency benchmark jup-ag/docs#939
• docs: link OpenChainBench public Injective RPC latency benchmark InjectiveLabs/injective-docs#182
• docs: link OpenChainBench public Neutron RPC latency benchmark neutron-org/neutron-docs#313
• docs: link OpenChainBench public Ink RPC latency benchmark inkonchain/docs#632
• docs: link OpenChainBench public Kaia RPC latency benchmark kaiachain/kaia-docs#437

Change

4 lines added to docs/protocol/infrastructure/vaas.md as a new ### Observed Finalization Latency subsection under ## Consistency and Finality. Uses the existing MkDocs Material link style ({target=\_blank}). No new dependencies, no navigation changes, no components introduced.

Disclosure

I maintain OpenChainBench. No affiliation with Wormhole Foundation. Happy to relocate the section, reword, or drop the GitHub source link if preferred.