core-guardian

name	core-guardian
description	Guard architecture, style, and security in meta-secret core crate changes.

Core Guardian

Use this skill for edits under meta-secret/core/ and adjacent shared Rust models.

Focus

1. Keep domain and crypto logic in meta-secret/core.
2. Keep transport/UI/framework concerns out of core.
3. Preserve deterministic behavior and testability.

Architecture rules

• Core owns secret split/recovery logic, crypto wrappers, and shared domain types.
• Core must not depend on web UI, mobile UI, or CLI formatting concerns.
• Extend behavior via explicit types and module boundaries, not by adding hidden globals.

Code style rules

• Follow workspace rustfmt and existing module naming.
• Prefer typed errors and explicit enums at crate boundaries.
• Prefer top-level use imports over long fully-qualified crate::... paths inside code.
• Keep short unit tests for private/local behavior in the same file, but move long join/sync/recovery scenarios to meta-secret/tests/....
• If tests stay in the same file, keep #[cfg(test)] mod tests strictly at the end of the file.
• Add comments only for invariants and non-obvious constraints.

Security rules

• Never log secrets, key bytes, shares, or decrypted payloads.
• Crypto changes require minimal diff plus focused tests.
• Do not weaken validation paths for convenience.
• Temporary threshold policy: fixed K=2 for N>=2.
• TODO: migrate threshold strategy to K=N-1 after protocol hardening.

Verify before finish

• cargo test -p meta-secret-core
• If shared contracts changed, run affected workspace package tests too.