Event commands (list, subscribe, schema)

Wire the events subcommand on top of the Bark EventService client. Blocked on the Bark EventService implementation (blinklabs-io/bark#18).

Scope:
- events list (event types available on the connected node)
- events subscribe [--type ...] [--filter ] (stream events to stdout in the chosen output format)
- events schema (print the schema for a given event type)

Notes:
- subscribe must handle disconnects cleanly and exit with a useful status code on signal
- subscribe should support both at-most-once (Subscribe) and reliable (SubscribeWithAck) modes via a flag
- Output respects --output; default is text but JSON is the practical scripting choice

Acceptance:
- list, subscribe, and schema work against a test bark server
- subscribe survives a transient disconnect when in reliable mode
- Signal handling exits cleanly without truncating in-flight output

Start by locating the events subcommand and the Bark EventService client, then verify the available client operations against a test Bark server. Implement and exercise list, subscribe, and schema with the documented output modes, reliable subscription behavior, disconnect handling, and clean signal termination without truncating in-flight output.

Written by the indexing model from the issue text.