One place to get an episode's file where you are (#457)

Getting an episode onto a phone took two buttons in two states: download
it to the server, wait, then keep it on the device, beside Save to this
computer, Share and Delete, five buttons that did not say where each
copy went. Now a file has one button that brings it to where you are.
On a phone or in the iOS app it ends on the device; when iPX has not got
the file yet, iPX fetches it and the device's copy follows once iPX says
it is done (remembered in localStorage, so a page closed meanwhile
catches up when a list next shows the file). On a computer it has iPX
fetch the file, and with iPX's copy there saves one. A line beside the
size says where the file is, and the rarer actions, two of them
destructive, are under a menu.

isPlayable is false for any file not on iPX, so the phone's button is
decided by playsKind, the same test without the path. download_done now
marks the file as on iPX in what the page holds, so the open file's box
changes at once rather than after the list is fetched again.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RqkrVA8TdTxe556JB3sR1n

web/CHANGELOG.md

@@ -44,6 +44,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- A file has one button that brings it to where you are: on a phone or in the iOS app it ends on the device, with iPX fetching it first when it has not got it, and on a computer iPX fetches it and the button then saves a copy. A line beside the file's size says where it is (publisher only, queued for iPX, on iPX, on this device), and the rarer actions (remove from this device, delete from iPX, download to iPX only) are under ⋯ (#457).
 - The admin page is laid out as a feed's settings are: each tab in named parts, numbers with their unit beside them, switches for on and off, Server's Save always in reach, and on a phone the tabs in a row of their own so all four fit (#414).
 - An item's title and text take four fifths of the reading pane's width, no longer running to its far edge (#360).