v0.2.0

Rebases pytruenas' generic host machinery onto [hostctl], keeping only the
TrueNAS-specific parts here: the middleware websocket, the api namespace,
login/2FA, subscriptions, and the upload/download side channels. Everything
else — shell quoting, transport selection, the asyncssh lifecycle, path
backends — is now inherited.

Requires hostctl>=0.1.0,<0.2.

Changed

• BREAKING: TrueNASClient.shell is gone. .shell now means what it means
  throughout hostctl — the bound shell object (client.shell.run(...)). The
  SSH connection target lives on the configuration as client.config.ssh, an
  SshConfig. The constructor argument is still spelled shell= and still
  takes a connection string (shell="ssh://root@nas").
• .run() and .path() now select a transport rather than branching.
  Which one serves a call is chosen from the available providers, and
  .last_selection records what was tried and why — with credentials redacted.
  Previously .run() hard-coded a local-vs-SSH branch and TruenasPath
  hand-rolled its own SFTP→websocket fallback.
• A remote target with no SSH can now run commands over the web shell. The
  TrueNAS JSON-RPC API exposes no remote command execution (verified against
  26.0.0-BETA.1: of 781 methods only core.resize_shell and
  user.shell_choices are shell-adjacent, and the former only resizes an
  already-open session) — so such a host previously had no run() at all.
  /websocket/shell, the PTY the web UI's Shell page drives, is a real command
  channel on the same port. Pass executor=["ssh"] to require SSH instead.
• The scheme/API-path probe moved from construction to first connect.
  TrueNASClient("bad-host") now constructs successfully and raises on first
  use. Configs are therefore buildable offline, which is what HostConfig
  requires.

Added

• pytruenas.host — TrueNASConfig (a hostctl.host.HostConfig) and
  TrueNASHost (a PosixHost). HostConfig("truenas+wss://nas") resolves
  through hostctl's registry; every connection string TrueNASClient accepts
  still works, normalized to a truenas+* scheme.
• TrueNASClient and TrueNASHost are now one class. They were briefly
  two objects that forwarded halves of their surface to each other —
  client.run() called client.host.run() while host.api called
  host.client.api, each holding a reference to the other. TrueNASClient is
  an alias for TrueNASHost, so every existing import and call keeps working,
  and client.host / host.client both return the object itself.
  TrueNASHost("wss://nas") also takes a connection string directly, with the
  same options as TrueNASConfig.from_target.
• pytruenas.providers — TnasWsPathProvider (the filesystem.*
  websocket leg) and local_providers(), which returns hostctl's stock local
  executor and path providers unchanged. A local target runs plain
  subprocess and uses plain local paths; there is nothing TrueNAS-specific to
  add, so pytruenas defines no provider class for it.
• pytruenas.webshell — WebShellExecutorProvider, command execution over
  /websocket/shell. Ordered after SSH; declares its limits rather than hiding
  them (stdout and stderr are one stream, no piped input, single-line commands
  only — pipes and here-strings work, being ordinary shell syntax).
• executor= / path= on TrueNASConfig — name the providers to use, in
  preference order, as a single name or a sequence: executor=["ssh"],
  path=["local", "tnasws"], executor=[] for no command channel at all.
  Unknown names, and ssh/sftp without an SshConfig, raise rather than
  composing a host that would fail later. Matches hostctl's own
  SystemConfig(executor=..., path=...) spelling.
• Credentials.from_host_credentials() — maps hostctl's already-parsed
  credential mapping (including a URI-supplied OTP) onto a Credentials
  subclass, with no second round of string parsing.
• Inherited from hostctl: .capabilities (so a host that genuinely cannot
  run commands says so up front rather than failing mid-call),
  .last_selection, .info(), .spawn(), .connect()/.close(), and
  context-manager support.
• black in the dev extra, pinned to the 3.9 floor.

Removed

• BREAKING: pytruenas.jsonrpc is now pytruenas.connection, and its
  Client class is TrueNASWSConnection. Client was doubly wrong: the class
  is not generic JSON-RPC (it knows core.subscribe, TrueNAS error codes, and
  the middleware unix socket), and the name collided with TrueNASClient.
  client.conn is the connection, with .websocket kept as an alias.
• BREAKING: pytruenas.client and pytruenas._conn are gone.
  from pytruenas import TrueNASClient is unaffected. _conn was a re-export
  shim for swapping the client implementation, which never happened; client
  had been reduced to an alias by the host/client merge.
• ~190 lines of generic host machinery: shell quoting, the local-vs-SSH branch
  in run(), the asyncssh connection, and _shellquote.

Known limitations

• A local unix-socket client cannot use download(). The HTTP side channel
  resolves to https://localhost and trips the appliance's self-signed
  certificate. This is pre-existing and unrelated to the migration — the URL
  construction is byte-identical to 0.1.1.
• The web shell merges stdout and stderr (a PTY is one stream), takes no
  piped input=, and requires single-line commands. Pipes and here-strings
  work, being ordinary shell syntax. It is ordered after SSH for these reasons.

Full Changelog: v0.1.1...v0.2.0