D043 - Naming a field is not the same as being able to write one

The superblock is now readable field by field, and Superblock exposes all of it rather than the four numbers a reader needs - because keeping only those is exactly what left the rest looking like a wall.

That does not mean filesystem writing is done. What remains is real work rather than missing knowledge: building an inode table, directory entries and a block allocation from a directory of files, then compressing to PFSC and encrypting under XTS. LibOrbisPkg/PFS carries PFSBuilder.cs, FSTree.cs, FlatPathTable.cs and PFSCWriter.cs for exactly those steps, so the source problem is closed and an effort problem is what is left.

Recorded so the distinction survives: item 4 moves from "blocked on a source" to "not written yet", and those are different entries in a backlog.