Implements gateway-level JWT validation for SQS requests: - Validates JWT signature against Authentik JWKS - Verifies claims: iss, aud, exp, nbf (with 60s skew) - Checks 'permissions' claim for sqs:read/sqs:write/wildcard - Returns 403 with error details on validation failure - JWKS caching with 15min TTL and auto-refresh on key rotation Architecture: - SQS: Gateway validates JWT (kmsvc code unverified) - MinIO, Temporal: Native JWT support (pass-through) - Memory, IAM: Service-owned JWT validation Integration tests added: - Reject requests without Authorization header (403) - Accept requests with valid JWT from Authentik - Pass through Authorization header unchanged for other services Uses github.com/MicahParks/keyfunc/v2 for JWKS handling: - Automatic refresh every 15 minutes - On-demand refresh if kid not found - Handles RS256 signatures