Evaluate near-cryptohash-rs extraction

[r-near]

Context

CryptoHash is duplicated across the ecosystem:

• nearcore/core/primitives-core/src/hash.rs (canonical, with ProtocolSchema derive)
• near-workspaces-rs/workspaces/src/types/mod.rs (copy with sha2 dep)
• near-api-rs/types/src/lib.rs (another copy)
• near-cli-rs (wrapper around near-primitives)

Action

• Evaluate whether a standalone near-cryptohash-rs crate is worth the coordination cost
• Prototype a minimal crate (sha256-based hash only, no ProtocolSchema)
• Determine if nearcore could wrap/extend it vs. the other way around
• Assess downstream migration effort

Considerations

• nearcore's version has ProtocolSchema derive (protocol-level concerns)
• Other consumers just need the basic hash functionality
• Coordination cost vs. deduplication benefit

Reference

• Slack thread: https://nearone.slack.com/archives/C0A64SAMDNG/p1767726931086969
• PR: Add NEAR Rust DevTools 2025 status update docs#2929

Priority: Medium