feat(cognition): wire check redundancy IPC

[joelteply]

Summary

• add Rust async evaluate_redundancy orchestration for cognition/check-redundancy
• build JSON-constrained provider requests with persona/room attribution and model override support
• wire CognitionModule command handling to return typed RedundancyDecision responses

Proof

• cargo test --manifest-path src/workers/continuum-core/Cargo.toml --lib --features metal,accelerate cognition::check_redundancy:: (22/22)
• npm run build:ts
• precommit: TS build, clippy baseline, cleanup
• pre-push: TS clean, ESLint baseline held, Rust compile clean, Rust tests passed
• pre-push Docker: core linux/arm64 image built; runtime slice refused boot because container exposes no GPU and strict no-CPU-fallback panic fired (gpu/memory_manager.rs:775)

Notes

• no TS shim in this PR; PR-3 can collapse TS caller onto this IPC
• no fallback/default-on-error path; provider and parse failures propagate as errors