feat: Add extraEnv to the File Server, Tool Call Server and Egress Gateway - #392

Summary

Only api and workerSandbox accept extraEnv. The README says to "Set REDIS_TLS=true via extraEnv on each component" to use TLS with Redis, but fileServer, toolCallServer and egressGateway also connect to Redis and don't accept extraEnv, so a Redis that requires TLS can't be used today.

This PR adds extraEnv to fileServer, toolCallServer and egressGateway, rendered after each component's own variables, as api and workerSandbox already do.

It also updates the README to list the components that need REDIS_TLS.

Testing

• helm template with values-local.yaml renders identically before and after this change.
• Setting extraEnv on each of the three components adds the variable to that component's container only.
• Each of the three components already reads REDIS_TLS (file-server.ts, tool-call-server.ts, egress-ledger.ts) so this should be the only bit that's missing.