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

.gitignore

@@ -1,8 +1,25 @@
 .*
-__pycache__
-temp
+__pycache__/
+temp/
 *.db
 *.egg-info/
 .venv/
 build/
 dist/
+
+# Local configuration (do not commit secrets or device-specific state)
+config/sensorpajen.env
+config/sensors.json
+config/discovered_sensors.json
+
+# Packaging build artifacts
+debian/.debhelper/
+debian/*.debhelper.log
+debian/*.log
+debian/*.substvars
+debian/debhelper-build-stamp
+debian/files
+debian/sensorpajen/
+
+# Local experiments
+test-local-tui/