Fix systemd instance files after the peer_id renames

[mikelangmayr]

• five instance files still pointed at configs deleted by the acronym rename (pickoff, rlight, msel, focpupsel, atcpickoff), so those units could never start; renamed to feipo, lsm, ms, atcl, atcp with their config paths updated
• added the ten instances that had no file at all: atcfw, piaagimb, piaagimr, hkettherm, yjettherm; coverage is now all 22 configs under config/hsfei and config/hscal
• WorkingDirectory moves from /opt/hispec/app to /var/log/hispec. The drivers write their own .log into the working directory, and the repo checkout is root-owned, so hsfei_atcpress died on startup with "Permission denied: /opt/hispec/app/inficonvgc502.log". /var/log/hispec is already created group-writable by install.sh
• README instance table regenerated from the instance files themselves, so the names cannot drift from reality again
• README now states the polkit rule needs polkit 0.106+ (Ubuntu 22.04 and later), since on an older host it is ignored silently and operators just get an auth prompt
• verified every instance resolves to an existing config and daemon script, and systemd-analyze verify passes on the unit