feat(desktop): a product sets the prefix of an app window's title

[doodlewind]

The title of an installed app's window, in its caption and its task button, was PocketJS: <app title>, written as a string in the System UI. A product that installs this System UI can now set the prefix.

The option

windowTitlePrefix in pocket.about.json, the file beside the System manifest that holds a product's About text since #28:

{
  "body": ["The desktop in your room."],
  "link": "example.org",
  "windowTitlePrefix": "My Desktop"
}

• A file without the field gives PocketJS. This repository's pocket.about.json does not set it, so its desktop reads PocketJS: Hero as before.
• An empty string titles the window with the app's title alone.
• The System UI's own windows (Notepad, Minesweeper, the folders, About) take no prefix, as before.

Why this file and not pocket.system.json: the System manifest's schema is PocketJS's (contracts/spec/pocket-system.ts) and sets additionalProperties: false, so a new field there needs a schema change and a new pin in every product. #28 put the About text beside the manifest for the same reason.

What changed

• shells/desktop/src/system-ui/pocket-apps.ts: readWindowTitlePrefix, WINDOW_TITLE_PREFIX, DEFAULT_WINDOW_TITLE_PREFIX and appWindowTitle(title).
• shells/desktop/src/system-ui/app.tsx: the one place that titled an app's window calls appWindowTitle.
• shells/desktop/test/system-ui-sim.test.ts: the titles it looks for come from appWindowTitle, so the test follows the file.
• shells/desktop/test/system-ui.test.ts: the default, a product's value, an empty value, values of other types, and that the About text reads the same with the field beside it.
• shells/desktop/README.md: the field, beside the About text.

Checks

bun run check at cd12366: exit 0 (asset check, typecheck of every shell, and the 3DS, iPod, desktop and touch tests, the desktop's simulator, wrap and text suites among them).

Not verified

The simulator runs this repository's own bundle, which uses the default. A bundle built with another prefix is covered by the unit tests of the two functions, not by a simulator run. Pocket Studio will build one and holds its own test to it.

🤖 Generated with Claude Code