feat: add fnOS packaging, storage workflows and release pipeline

fnos/cmd/upgrade_init

@@ -0,0 +1,23 @@
+#!/bin/bash
+set -eu
+
+DATA_ROOT="${TRIM_APPDEST_VOL}/@appshare/dy.net"
+DB_ROOT="${DATA_ROOT}/db"
+DB_FILE="${DB_ROOT}/dy.sqlite"
+BACKUP_ROOT="${DB_ROOT}/upgrade-backups"
+
+if [ ! -f "${DB_FILE}" ]; then exit 0; fi
+
+mkdir -p "${BACKUP_ROOT}"
+DEST="${BACKUP_ROOT}/fpk-pre-0.2.25-$(date '+%Y%m%d-%H%M%S')"
+mkdir -p "${DEST}"
+cp -p "${DB_FILE}" "${DEST}/dy.sqlite"
+if [ -f "${DB_FILE}-wal" ]; then cp -p "${DB_FILE}-wal" "${DEST}/dy.sqlite-wal"; fi
+if [ -f "${DB_FILE}-shm" ]; then cp -p "${DB_FILE}-shm" "${DEST}/dy.sqlite-shm"; fi
+if [ -d "${DB_ROOT}/keys" ]; then cp -a "${DB_ROOT}/keys" "${DEST}/keys"; fi
+
+# Avoid GNU find -printf: fnOS releases may provide the BusyBox find implementation.
+ls -1dt -- "${BACKUP_ROOT}"/* 2>/dev/null | tail -n +4 | while IFS= read -r backup; do
+    if [ -d "${backup}" ]; then rm -rf -- "${backup}"; fi
+done
+exit 0