revert: remove raw proof context escape hatch

[pgherveou]

Summary

• remove the development-only raw ring-VRF proof context escape hatch
• restore product-scoped context derivation at all signing and pairing call sites
• remove the temporary TypeScript helper, tests, exports, and documentation

Why

PR #457 deliberately allowed products to mint proofs in contexts they do not own so the Humanity flow could be exercised end to end. That workaround has served its purpose and must not ship as a permanent weakening of product context isolation.

This intentionally removes the exported development_createAccountProof helper and stops treating the raw: product marker specially.

Verification

• make check
• RUSTFLAGS='-D warnings' cargo build --workspace --all-targets --all-features
• make uniffi-kotlin
• gradle :truapi-host:assembleRelease with Gradle 8.9 and JDK 17
• exact tree match with the parent of squash commit 8983638b
• matching stable patch IDs for the original change and its reverse
• git diff --check

Reverts #457.