`polkit`

Strand's own polkit authentication agent: the password dialog when a program asks for something that needs one. While a config reads polkit, Strand registers as this session's agent with polkit (unless another agent already is, which it leaves be), and each request polkit sends becomes request until it is answered, cancelled, or withdrawn by the program. The password goes to polkit's own helper (polkit-agent-helper-1), never checked by Strand, and is wiped once sent. A panel shows it: panel Polkit { open: polkit.request != null; keyboard: exclusive … }.

Field	Type
`request`	`PolkitRequest?`	The request being answered, or null when none waits.
`waiting`	`int`	How many more requests wait behind `request`, each shown in turn.
`busy`	`bool`	An answer is being checked.
`failed`	`bool`	The last answer was refused: `request` stays, and its prompt asks again.
`available`	`bool`	Strand is this session's polkit agent. False while another agent is (a desktop's own, `polkit-gnome`), and when it cannot be one: polkit's helper (`polkit-agent-helper-1`, setuid root, or polkit's own socket for it) is not installed, polkit is not running, or Strand runs in no login session; `error` says which.
`error`	`text`	Why Strand is not the agent ("another polkit authentication agent already serves this session…"), or why the shown request's check could not run or ended early; "" otherwise.

Method
`action respond(answer: text)`	Answers `request.prompt` with `answer` (the password): `input { type: password; text: <-> pw; on activate { polkit.respond(pw); pw = "" } }`. Ignored while one is being checked, and when the request shown has not asked yet (it went, or another user was chosen, since the answer was typed: an answer is never given to a request it was not typed for). After a refusal an answer typed before the check asks again waits for that question, and only a secret one (not `echo`) takes it. Pass a password to nothing else: the config is trusted code, and a declared action's arguments can be read by every user in the process list.
`action cancel()`	Dismisses `request`: the program is told it was refused, and the next request, if any, shows.
`action choose(user: text)`	Asks for `user`'s password instead (one of `request.users`).