fix: discover existing MySQL client tools

deploy/update.sh

@@ -575,6 +575,30 @@ application_state() {
   fi
 }
 
+mysqldump_bin() {
+  if [ -n "${KAIDI_MYSQLDUMP_BIN:-}" ]; then
+    case "$KAIDI_MYSQLDUMP_BIN" in
+      */*) [ -x "$KAIDI_MYSQLDUMP_BIN" ] && printf '%s\n' "$KAIDI_MYSQLDUMP_BIN" && return 0 ;;
+      *) candidate=$(command -v "$KAIDI_MYSQLDUMP_BIN" 2>/dev/null || true); [ -n "$candidate" ] && printf '%s\n' "$candidate" && return 0 ;;
+    esac
+    return 1
+  fi
+  candidate=$(command -v mysqldump 2>/dev/null || true)
+  if [ -n "$candidate" ]; then
+    printf '%s\n' "$candidate"
+    return 0
+  fi
+  for candidate in \
+    /www/server/mysql/bin/mysqldump /usr/bin/mysqldump \
+    /usr/local/mysql/bin/mysqldump /opt/mysql/bin/mysqldump; do
+    if [ -x "$candidate" ]; then
+      printf '%s\n' "$candidate"
+      return 0
+    fi
+  done
+  return 1
+}
+
 backup_database() {
   DATABASE_BACKUP=
   [ "${KAIDI_SKIP_DB_BACKUP:-false}" = "true" ] && return
@@ -594,11 +618,12 @@ backup_database() {
       fail "Database backup failed"
     fi
   else
-    command -v mysqldump >/dev/null 2>&1 || {
+    dump_bin=$(mysqldump_bin || true)
+    [ -n "$dump_bin" ] || {
       rm -f "$dump_file" "$backup_tmp"
-      fail "mysqldump is required before installing an update"
+      fail "mysqldump is required before installing an update; set KAIDI_MYSQLDUMP_BIN or install it in a standard MySQL bin directory"
     }
-    if ! MYSQL_PWD=${KAIDI_DB_PASSWORD:-} mysqldump --single-transaction --routines --triggers \
+    if ! MYSQL_PWD=${KAIDI_DB_PASSWORD:-} "$dump_bin" --single-transaction --routines --triggers \
       -h "${KAIDI_DB_HOST:-127.0.0.1}" -P "${KAIDI_DB_PORT:-3306}" \
       -u "${KAIDI_DB_USERNAME:-kaidi}" "${KAIDI_DB_NAME:-kaidi_finance}" > "$dump_file"; then
       rm -f "$dump_file" "$backup_tmp"