Fix installed service and launcher paths; wait for the pointer helper

The service and menu-entry templates still pointed at the old frametop/
subfolder, so the pointer helper, input relay, and settings apps couldn't
start after a clean install. The pointer helper's install step also failed
when the service was still starting after 3 s; it now waits up to 20 s and
doesn't abort the installer.

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

pointer/helper/frametop-pointer.service

@@ -1,7 +1,7 @@
 # Template: the installer replaces @REPO@ with the repo path on the Frame.
 [Unit]
 Description=Frametop pointer helper: the universal 3D mouse (cursor, collision, ft_pointer driver)
-Documentation=file://@REPO@/frametop/README.md
+Documentation=file://@REPO@/README.md
 # Needs SteamVR's IPC; it starts and stops with SteamVR.
 After=steamvr.service frametop-input-relay.service
 PartOf=steamvr.service
@@ -10,7 +10,7 @@ PartOf=steamvr.service
 # Runs in the dev container (built there against its libraries). The helper process
 # lives in the container, so clean it up explicitly around distrobox enter.
 ExecStartPre=-/usr/bin/pkill -x ft-pointer
-ExecStart=%h/.local/bin/distrobox enter dev -- @REPO@/frametop/pointer/helper/build/ft-pointer
+ExecStart=%h/.local/bin/distrobox enter dev -- @REPO@/pointer/helper/build/ft-pointer
 ExecStopPost=-/usr/bin/pkill -x ft-pointer
 Restart=on-failure
 RestartSec=3