Add CLI helper for entropy volume

docs/Dankserver/Entropy Volume.md

@@ -0,0 +1,43 @@
+# Entropy Volume
+
+The Dankserver entropy volume is a RAID-backed LUKS filesystem mounted at
+`/mnt/entropy`. The command-line helper reuses the host's desktop-integrated
+`udisks2`, `crypttab`, and `fstab` configuration; it does not store or handle
+the passphrase itself.
+
+## Command-line mount
+
+```bash
+/home/dank/serverAppConfigs/scripts/mount-entropy.sh
+```
+
+Run it as the normal desktop user (`dank`), not from a root shell. `udisksctl`
+will securely prompt for the LUKS passphrase. `sudo mount /mnt/entropy` then
+uses the existing `/etc/fstab` entry, preserving its options:
+
+```text
+nosuid,nodev
+```
+
+The existing mountpoint is owned by `dank:dankserver` with mode `0755`; the
+helper deliberately does not run `chmod` or `chown`, so it cannot silently
+change those permissions.
+
+## Device path
+
+The current storage chain is:
+
+```text
+/dev/md0 -> LUKS UUID cd86c728-459e-4f3a-bcc2-41ecf84685ec
+         -> ext4 label entropy
+         -> /mnt/entropy
+```
+
+The helper checks that `/dev/md0` exists and exits successfully if the volume
+is already mounted. It is intentionally specific to this host and volume:
+that avoids accidentally unlocking or mounting a different disk.
+
+## Related
+
+- [[Storage Policy]]
+- [[Dankserver Stack]]