chore: initial import of backup scripts and design docs

Existing borg-backup.sh/dump_db.sh, old/ reference scripts, and the
brainstormed design spec for restore tooling + runbook.

old/maria.sh

@@ -0,0 +1,36 @@
+root@chaudron:/home/srv/files/content/mariadb# cat dump_db.sh
+#!/bin/bash
+
+# Load configuration from environment variables
+MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD:-MySuperDatabase}
+DUMP_DIR=${DUMP_DIR:-dump}
+DOCKER_CONTAINER_NAME=${DOCKER_CONTAINER_NAME:-mariadb}
+
+# Check dependencies
+if ! command -v docker &>/dev/null; then
+  echo "Docker is not installed or not in the PATH"
+  exit 1
+fi
+
+if ! docker ps -q -f name=$DOCKER_CONTAINER_NAME; then
+  echo "Docker container '$DOCKER_CONTAINER_NAME' is not running"
+  exit 1
+fi
+
+# Create dump directory if it doesn't exist
+mkdir -p "$(dirname "$0")/$DUMP_DIR"
+
+# Delete old dump files
+rm -f "$(dirname "$0")/$DUMP_DIR"/*.sql
+
+# Get list of databases and exclude system databases
+databases=$(docker exec -it $DOCKER_CONTAINER_NAME mysql -u root -p"$MYSQL_ROOT_PASSWORD" -e "SHOW DATABASES;" --skip-column-names -s | grep -Ev "(information_schema|mysql|performance_schema|sys)" | tr -d '\r')
+
+# Iterate through databases and dump them individually
+for db in $databases; do
+  echo "Dumping database: $db"
+  docker exec -i $DOCKER_CONTAINER_NAME mysqldump -u root -p"$MYSQL_ROOT_PASSWORD" "$db" >"$(dirname "$0")/$DUMP_DIR/$db.sql"
+  echo "Dumped database: $db"
+done
+
+echo "All non-system databases dumped to individual files in '$DUMP_DIR' directory."