Remove break-lock, add checking, and fix healthcheck

src/borg-common.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+export BORG_RSH='ssh -oBatchMode=yes'
+
+# Never break another client's repository/cache lock. Borg 1.4 only accepts
+# finite waits, so retry lock timeouts forever; other errors must propagate.
+borg_wait() {
+    local status
+    while true; do
+        if BORG_EXIT_CODES=modern borg "$@" --lock-wait=60; then
+            return 0
+        else
+            status=$?
+        fi
+        if (( status != 73 )); then
+            return "$status"
+        fi
+        echo "Repository or cache is locked; continuing to wait..." >&2
+    done
+}