fix(bazarr): store data in /var/lib/bazarr instead of inside /opt/bazarr (#16098)

* fix(bazarr): store data in /var/lib/bazarr instead of inside /opt/bazarr

The installer creates /var/lib/bazarr and update_script() uses it as the
"is Bazarr installed" guard, but nothing pointed Bazarr at it. Bazarr
defaults its data directory to <install dir>/data, resolved from its own
source file rather than WorkingDirectory, so a stock container kept
config/ db/ backup/ cache/ log/ restore/ in /opt/bazarr/data - the
directory fetch_and_deploy_gh_release redeploys over - while
/var/lib/bazarr stayed empty.

Pass -c /var/lib/bazarr in the unit, matching the -data= flag the other
*arr scripts use. bazarr.py re-execs its child with sys.argv[1:], so the
flag survives the restart Bazarr performs while loading its config.

update_script() gains a one-time migration for existing installs. It runs
outside the release check so containers already on the latest version are
migrated too, is skipped when the unit already names a data directory,
refuses (before stopping the service) when both locations hold data, and
copies before removing so a failed migration leaves the original database
in place.

Fixes #16097

* fix(bazarr): drop explanatory comments per review

ct/bazarr.sh

@@ -28,6 +28,31 @@ function update_script() {
     msg_error "No ${APP} Installation Found!"
     exit
   fi
+
+  if ! grep -qE -- "bazarr\.py.*[[:space:]](-c|--config)([[:space:]]|=)" /etc/systemd/system/bazarr.service 2>/dev/null; then
+    if [[ -d /opt/bazarr/data && ! -L /opt/bazarr/data && -n "$(ls -A /var/lib/bazarr/ 2>/dev/null)" ]]; then
+      msg_error "/opt/bazarr/data and /var/lib/bazarr both contain data - refusing to merge them. Keep the copy you want in /var/lib/bazarr, remove /opt/bazarr/data, then run the update again."
+      exit 1
+    fi
+
+    msg_info "Moving Bazarr data to /var/lib/bazarr"
+    systemctl stop bazarr
+    if [[ -L /opt/bazarr/data ]]; then
+      rm -f /opt/bazarr/data
+    elif [[ -d /opt/bazarr/data ]]; then
+      if ! cp -a /opt/bazarr/data/. /var/lib/bazarr/; then
+        systemctl start bazarr
+        msg_error "Could not copy /opt/bazarr/data to /var/lib/bazarr - nothing was removed."
+        exit 1
+      fi
+      rm -rf /opt/bazarr/data
+    fi
+    sed -i -E "s|^(ExecStart=.*bazarr\.py.*)$|\1 -c /var/lib/bazarr|" /etc/systemd/system/bazarr.service
+    systemctl daemon-reload
+    systemctl start bazarr
+    msg_ok "Moved Bazarr data to /var/lib/bazarr"
+  fi
+
   if check_for_gh_release "bazarr" "morpheus65535/bazarr"; then
     msg_info "Stopping Service"
     systemctl stop bazarr

install/bazarr-install.sh

@@ -36,7 +36,7 @@ UMask=0002
 Restart=on-failure
 RestartSec=5
 Type=simple
-ExecStart=/opt/bazarr/venv/bin/python3 /opt/bazarr/bazarr.py
+ExecStart=/opt/bazarr/venv/bin/python3 /opt/bazarr/bazarr.py -c /var/lib/bazarr
 KillSignal=SIGINT
 TimeoutStopSec=20
 SyslogIdentifier=bazarr