Launch apps floating, remember where they floated, and Launch as Standalone

ft-float launch APP / run COMMAND: ft-floatd starts the app and floats its
first window (matched by process or desktop file name for 30 s) where that
app last floated, or in front of you at the primary screen's density. Each
app's place (pose relative to the primary screen, size in pixels, scale) is
kept in ~/.config/frametop-float.json whenever one of its windows stops
floating; the scale isn't applied yet, since rescaling can loop (written up
in docs/floating-windows.md, Known problems).

Launch as Standalone (float/ft_apps.py): the session writes copies of the
apps' desktop files with that action and puts them first in XDG_DATA_DIRS,
so it shows in the Application Launcher's and the taskbar's right-click menus
in the Frametop desktop only. ft-floatd rewrites them when apps change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -55,6 +55,7 @@ If you work in the desktop for long stretches, or leave the headset on a stand,
 | Save current arrangement… (Frametop Display Settings, Layout) | Saves where the screens are, with their sizes and pins, under a name. Pick a saved layout under Arrangement and press Arrange now to switch to it |
 | Meta+Shift+R in the desktop | Puts the screens back in their layout (also in the menu as Reset Screen Layout, and mappable to a mouse button) |
 | Meta+Shift+F over a desktop window | Floats that window in VR as a panel of its own, or puts it back on its screen if it floats. It acts on the window under the pointer, or the active one if the pointer is over the wallpaper. Rebind it, or map it to a mouse or controller button, in Frametop Input Settings (Keyboard page, or Buttons and Controllers as Float window in VR). Float in VR is also in every window's menu (Alt+F3), and the button left of Close in a window's title bar does the same (apps that draw their own title bar, like Chromium and Electron apps, don't have it) |
+| Right-click an app in the Application Launcher (or the taskbar) and pick Launch as Standalone | Starts the app with its window floating in VR, where that app last floated, or in front of you the first time. From a terminal: `float/ft-float launch org.kde.dolphin`, or `float/ft-float run <command>` |
 | Meta+Shift+H in the desktop | Hides or shows all screens (also in the menu as Hide/Show Screens, and mappable). The Visibility & pins tab of Frametop Display Settings can instead show them only with the dashboard open, or while you look at your wrist |
 | Leave the headset on a stand | Its displays turn off once it has gone unused for the time set in Frametop Display Settings → Power, even if the stand covers its proximity sensor. Pick it up, or use any mouse, keyboard, or button, and they come back on |
 | Play a VR game | The screens hide and your controllers stay in the game. Open the SteamVR dashboard, or press Meta+Shift+H, to see and use them. To keep them visible over games, change During VR games on the Visibility & pins tab; the controllers still stay in the game, and you use the screens with the mouse or the dashboard |