Restructure project documentation

Separate operator guides from development contracts, relocate
implementation notes under `docs/devel/`, and update cross-references
and
hardware tooling paths. Add getting-started, user administration, and
firmware update guides while preserving firmware behavior.

hardware/PCB/validation/pcb-routing-reposition.py

@@ -69,10 +69,14 @@ def main():
     before=PCB.read_bytes()
     assert before==BACKUP.read_bytes(), 'current board differs from A0 snapshot; refusing migration'
     protected=[ROOT/name for name in ('serial-carrier.kicad_pro','serial-carrier.kicad_sch',
-                'serial-carrier.kicad_prl','README.md','pcb-draft-notes.md','fp-lib-table',
+                'serial-carrier.kicad_prl','README.md','fp-lib-table',
                 'sym-lib-table','Carrier.kicad_sym')]
     protected+=list((ROOT/'Carrier.pretty').glob('*'))
     hashes={str(path.relative_to(ROOT)):sha(path) for path in protected if path.is_file()}
+    # Keep report keys relative to ROOT, including the relocated, required note.
+    # Do not silently omit it through the optional project-file filter above.
+    notes='../../docs/devel/hardware/PCB/pcb-draft-notes.md'
+    hashes[notes]=sha(ROOT/notes)
     board=p.LoadBoard(str(PCB))
     immutable=normalized_footprints(board)
     net_table=identity(board)[-1]