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>

README.md

@@ -188,7 +188,7 @@ The extension creates several tables:
 ├── config.json              # Extension configuration
 ├── manifest.json            # Extension manifest
 ├── templates/
-│   └── satmachineadmin/
+│   └── spirekeeper/
 │       └── index.html       # Main UI template
 └── static/
     └── js/