[Feature] ShardedDaemonProcess keys — keep-alive interval and role

[pathosDev]

Use case

ShardedDaemonProcessOptions.livenessIntervalMs (the keep-alive ping that revives daemons) and the hosting role are code-only. Both are deployment tuning.

Proposed keys

actor-ts.sharded-daemon-process {
  keep-alive-interval = 30s
  role = ""
}

Acceptance

• Both values reach daemon-process instances started without explicit options; explicit options win.
• Keys ship wired — tests/unit/config/NoDeadConfigKeys.test.ts rejects a key nothing reads.

Part of the reference.conf expansion batch — tracked in #887.