Update storage profiles documentation for postTeardown and rabbitPostTeardown

[ajfloeder]

Summary

Updates the Storage Profiles guide to document the postTeardown and rabbitPostTeardown user command hooks added in the latest nnf-sos release.

Changes

• Storage-Level User Commands table: Add postTeardown — runs on the Rabbit after the file system and block devices are already destroyed (Teardown phase)
• Storage-Level User Commands YAML example: Add postTeardown usage example with note that $MOUNT_PATH is not available
• Lustre Client Commands example: Add rabbitPostTeardown in clientCommandLines
• GFS2 YAML example: Add commented-out postTeardown showing the DLM diagnostics use case
• Storage-Level variable table: Add separate variable table for postTeardown with block device variables ($VG_NAME, $LV_NAME, $LV_INDEX, $DEVICE_*, etc.)
• Lustre Client variable table: Add rabbitPostTeardown variable table with zpool variables ($POOL_NAME, $DEVICE_*)
• Markdown lint fixes: Resolve all MD031/MD032/MD040/MD047/MD060 warnings

Key documentation notes

• Both postTeardown and rabbitPostTeardown run only on the Rabbit, never on Computes
• Both run after the file system and block devices are already destroyed — $MOUNT_PATH is not available
• For postTeardown (XFS/GFS2/Raw): use $VG_NAME, $LV_NAME, $DEVICE_* variables
• For rabbitPostTeardown (Lustre): use $POOL_NAME, $DEVICE_* variables