M5: deletion delay with trash, passphrase slots, ransomware documentation

- removed snapshots go to a trash on the location and their data is only
  freed after the deletion delay, which is chosen when the key is created
  (default 7 days, 1-365) and cannot be changed afterwards; any admin can
  bring them back (occ backup:trash, backup:trash:restore, web UI)
- up to three passphrase slots open the same master key (like LUKS), so
  one person leaving or dying does not lock the company out; slot changes
  are written to every location, announced to all admins and require a
  new recovery kit confirmation, while backups keep running
- occ backup:key:slots, backup:key:slot:add|replace|remove; key init takes
  --label and --delete-delay-days
- web UI: deletion delay and first slot at key creation, slot management,
  trash per location with restore; all behind password confirmation
- README: key, slots (safe / CTO / head of IT), and protection against
  ransomware: object lock in compliance mode (e.g. 90 days), credentials
  without delete rights, provider snapshots, off-site copy

appinfo/info.xml

@@ -5,7 +5,7 @@
     <name>NG Backup</name>
     <summary>Encrypted, incremental backups of your Nextcloud with restore from the web interface</summary>
     <description><![CDATA[Work in progress, not ready for use.]]></description>
-    <version>0.0.8</version>
+    <version>0.0.11</version>
     <licence>agpl</licence>
     <author>Dillard Blom</author>
     <namespace>NgBackup</namespace>
@@ -35,6 +35,12 @@
         <command>OCA\NgBackup\Command\Prune</command>
         <command>OCA\NgBackup\Command\Retention</command>
         <command>OCA\NgBackup\Command\TargetAppendOnly</command>
+        <command>OCA\NgBackup\Command\Trash</command>
+        <command>OCA\NgBackup\Command\TrashRestore</command>
+        <command>OCA\NgBackup\Command\KeySlots</command>
+        <command>OCA\NgBackup\Command\KeySlotAdd</command>
+        <command>OCA\NgBackup\Command\KeySlotReplace</command>
+        <command>OCA\NgBackup\Command\KeySlotRemove</command>
     </commands>
     <settings>
         <admin>OCA\NgBackup\Settings\Admin</admin>