feat: build access level labels from their bits and project names

Labels came from a fixed table matched by subset, so Storage (no bits)
matched any level the table lacked, and a level was named after the first
entry it contained: the server's Brain/MINDS 2.0 folders (0x10000) showed
as Storage and 0x10104 as CBS or PW Open.

Labels are now composed from the bits. Projects (bit 16 and up) take the
names the server reports to their members through users/current/, and
otherwise Project<n>; restrict slot 1 is CBS and any other Restrict<n>.
A level with no meaning is shown as Unknown (0x...). chacl reads keys
built the same way, refuses public and storage before any request, and
lists the user's projects with their keys when given an invalid level.

README.md

@@ -199,12 +199,14 @@ mdrs rm -r neurodata:/NIU/Repository/TEST/dataset
 
 ### chacl
 
-Change the folder access level
+Change the folder access level. The level is `private`, `pw_open`, `cbs_open`, `project<n>_open`, or several open levels joined by `_or_`. `<n>` is the project's bit position; an invalid level lists the projects you belong to with their keys.
 
 ```shell
 mdrs chacl private neurodata:/NIU/Repository/Private
 mdrs chacl cbs_open -r neurodata:/NIU/Repository/CBS_Open
 mdrs chacl pw_open -r -p SHARING_PASSWORD neurodata:/NIU/Repository/PW_Open
+mdrs chacl cbs_or_pw_open -p SHARING_PASSWORD neurodata:/NIU/Repository/CBS_or_PW_Open
+mdrs chacl project0_open neurodata:/NIU/Repository/Project_Open
 ```
 
 ### metadata