Rename Chronicle event-store-subscriptions command group to subscriptions

[Copilot]

Summary

Renames the Chronicle CLI command path from event-store-subscriptions to subscriptions for consistency and shorter invocation. Updates command registration, completion routing, examples, integration usage, and Chronicle docs to the new path.

Added

• None.

Changed

• Renamed the Chronicle branch command from event-store-subscriptions to subscriptions in CLI registration and command discovery.
• Updated dynamic completion keying for subscription removal to match the new command path.
• Updated command examples/help text to use cratis chronicle subscriptions ....
• Updated Chronicle documentation index/table/TOC labels and command invocations to subscriptions.

# before
cratis chronicle event-store-subscriptions list --event-store system

# after
cratis chronicle subscriptions list --event-store system

Fixed

• Updated integration scenario for add/list/remove subscription flow to invoke chronicle subscriptions instead of the old path.

Removed

• Removed remaining runtime references to event-store-subscriptions command invocation paths (except documentation file name event-store-subscriptions.md).

Security

• None.

Deprecated

• event-store-subscriptions command path is superseded by subscriptions.