Introduce a new single-process service runtime:

• Add Supervisor to create, run, stop, and tear down multiple services under one process.
• Services are created through factory functions that validate configuration and initialize service instances.
• SIGINT and SIGTERM are handled by the supervisor and translated into graceful shutdown. Unused SIGHUP reload support was removed.
• Child-service startup failures, unexpected exits, and shutdown errors are logged and propagated through the supervisor.
• Multiple errors are now returned as a single error using errors.Join.

Simplify the service lifecycle protocol:

• Service shutdown is now driven by context.Context cancellation.
• The previous service.stopping / IsStopping state and per-service Stop signaling were removed.
• Services that need to stop internal work, HTTP servers, tickers, or background loops must watch the provided context.
• Reload was removed because it was unused.
• Alive is no longer implemented per service. /livez is now supervisor-owned: it is true while the supervisor is serving and not stopping.
• Teardown was added so services can release resources after Serve exits, although it is not currently being used.

Add reusable service templates:

• TickServiceTemplate for tick-based services:
  • Advancer
  • Claimer
  • EVM Reader
  • PRT
  • Validator
• HTTPServiceTemplate for HTTP-backed services:
  • JSON-RPC
  • Inspector
  • Telemetry

Refactor supervised services:

• Inspector and JSON-RPC are now first-class supervised HTTP services.
• Inspector now uses the shared HTTP hardening and startup/shutdown path.
• Telemetry is now a built-in supervisor-managed HTTP service.
• The machine manager is created as a shared component before service startup and closed after services terminate, instead of being owned by Advancer teardown.

Update tick and context APIs:

• Functions that need a context now receive it as an argument instead of reading it from service state.
• Tick-based services now return (bool, error) from Tick; the boolean controls whether another immediate tick should be scheduled.
• Service APIs now return joined error values instead of []error.

Behavior changes to note:

• Supervisor shutdown is consistently triggered by context cancellation, OS signals, service initialization failure, or unexpected child-service exit.
• Listener failures and unexpected exits from Inspector or JSON-RPC now participate in supervisor shutdown like
  other service failures.