- Refactor network model types: replace `NetworkState` enum and
phase-based NetworkStatus with a flat `NetworkStatus` struct.
- Simplify API server ↔ plugin protocol: plugin `status()` returns
runtime status only, API server owns configuration.
- `NetworksService` `list()`/`create()` now return `NetworkResource`
directly.
- Remove lifecycle phase checks and state machine guards throughout CLI
and API server.
- `variant` is plugin-specific, it's not a required property. This PR
replaces `NetworkPluginInfo` with a `plugin` name property on
`NetworkConfiguration` and an `options` list similar to that for
volumes.
- Moved `variant` to the option list.
- Part of #1404.
- Evolves API to use NetworkResource that conforms to ManagedResource.
- BREAKING CHANGE - compile time impact due to changes to Swift client
API signatures. No change to persistent data or API server XPC
protocols.
- Part of #1404.
- COMPATIBILITY: Breaking change to client API. XPC protocol and
persistent data remain fully compatibile.
- Renames `ClientNetwork` to `NetworkClient`, aligning with
`ContainerClient`.
- Client uses instance methods instead of utility functions, with an
`init(serviceIdentifier:)` for the XPC service name. The value is
currently unused.