A plugin's <profile>.meta.json targets (web, mobile, desktop, widget; absent = web)
now decide where it is built. internal/plugin-targets.mjs is the one reading.
desktop:build builds a desktop plugin into .desktop/<plugin>/ with a page that
names its engine, builds its backend as a Tauri sidecar for this machine, and runs
tauri build with a --config override; tauri.conf.json and public/ are untouched.
The shell starts the bundled rudder-engine (RUDDER_AUDIO=browser, RUDDER_HOME in the
app data folder) and stops it on exit. A plugin whose targets leave out web
(Rudder: desktop + widget) is no longer built for the web tree: run-parallel,
generate-tree and check-composite-freshness skip it, and its public/ folder is
removed; the dev server still gives the Studio its corner. check:targets
(gates:pre, with a self-test of five planted violations) validates the values,
widget corners and backend folders and fails if a non-web plugin reaches the built
tree. Measured: desktop:build rudder-voice on Linux produced Rudder_0.1.0_amd64.deb
(8.8 MB) with the app and the engine side by side; the app has not been launched.