Add agent middleware integration

[Jason-Doyle]

Summary

• add framework-neutral agent middleware for bounded context compilation, model-facing JSON Schema tools, identity-bound Agent Intent dispatch, and durable approved-turn recording
• add embedded SQLite, in-process PostgreSQL, and authenticated remote HTTP adapters
• keep raw artifact, administrative, provider-owned, and timer operations outside the model surface by default
• add a complete host-to-model integration guide and runnable embedded and production examples
• refresh benchmark evidence from source commit e8b9767

Safety boundaries

• model arguments cannot provide tenant, principal, purpose, or API credentials
• operation permissions can only narrow the immutable safe allowlist
• context provenance distinguishes complete, partial, and omitted evidence
• HTTP responses are timed, byte-bounded, redirect-free, and correlated to request identity and result hashes
• turn artifacts use principal-scoped canonical hashes and separate idempotency domains

Validation

• npm run release:check
• full PostgreSQL integration suite
• npm run deployment:check
• package consumer and generated declaration smoke tests
• Ajv model-schema contract tests
• three-run SRE benchmark regeneration and verification
• independent design and code reviews