docs: update functional identifier refs to spirekeeper

Runbook SQL (spirekeeper.dca_*), ext URL paths, code-location paths,
and the DB-schema name in docs/CLAUDE/README move to the new identity.
Rewrites the placeholder description.md with a real one. Historical
aiolabs/satmachineadmin#N issue/repo links stay pointing at the
original repo.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -213,7 +213,7 @@ commission_amount = 266800 - 258835 = 7,965 sats (to commission wallet)
 ### Security Considerations
 - **Superuser Authentication**: Admin extension requires LNBits superuser login
 - **Wallet Admin Keys**: Client extension uses wallet admin keys for user operations
-- **Database Access**: Only superusers can write to satoshimachine database
+- **Database Access**: Only superusers can write to spirekeeper database
 - SSH tunnel encryption for database connectivity
 - Read-only database permissions for Lamassu access
 - Input sanitization and type validation
@@ -230,7 +230,7 @@ on existing installs:
 ```sql
 SELECT a.id, a.username, a.pubkey, m.id, m.machine_npub
 FROM accounts a
-JOIN ext_satoshimachine.dca_machines m
+JOIN ext_spirekeeper.dca_machines m
   ON LOWER(a.pubkey) = LOWER(m.machine_npub);
 ```