Add scripts and configuration files for mergerfs setup and testing

- Created backup files for wipefs on specific disk partitions.
- Added db-test script to verify metadata.db file integrity.
- Documented successful mergerfs branch and pool configurations in mfs-good.txt.
- Implemented mfs write test in mfs-test.txt.
- Included mergerfs version and device information in mfs.txt.
- Developed rebuild scripts for mergerfs stages, including verification and filesystem creation.
- Generated stage logs for each rebuild step to track disk and filesystem status.
- Added checks for systemd mount requirements and filesystem verification in stage4.

post-rebuild/stage1.txt

@@ -0,0 +1,11 @@
+=== /dev/disk/by-id/wwn-0x5000c500fde02343 ===
+sda   3.6T ST4000DM004-2U91 ZFN5VCSS
+=== /dev/disk/by-id/wwn-0x5000c500e70446ad ===
+sdb   7.3T ST8000DM004-2U91 ZR14W7C7
+=== /dev/disk/by-id/wwn-0x5000c500ebf2cd37 ===
+sdc   7.3T ST8000DM004-2U91 WSC2WN91
+=== /dev/disk/by-id/wwn-0x5000c500929c8d02 ===
+sdd   5.5T ST6000NM0004-1FT Z4D4NY1L
+
+=== OS — MUST NOT APPEAR ABOVE ===
+sde  223.6G ADATA SU635 2M232L1664TD