Release v3.0.0

- Bump version to 3.0.0 and update docs

- Fix Debian payload to include TUI and install /usr/bin/sensorpajen-tui wrapper

- Make systemd unit upgrades safer and ignore deb build artifacts

debian/sensorpajen-tui

@@ -0,0 +1,12 @@
+#!/bin/sh
+set -eu
+
+# Wrapper to run the installed TUI using the app's virtualenv.
+# The venv is created/updated by the package postinst.
+
+if [ -x /opt/sensorpajen/venv/bin/sensorpajen-tui ]; then
+  exec /opt/sensorpajen/venv/bin/sensorpajen-tui "$@"
+fi
+
+# Fallback (should normally not be needed)
+exec /opt/sensorpajen/venv/bin/python -m sensorpajen.tui.app "$@"