Update documentation and API tests: Bookmann → Bookhoard

Documentation updates:
- All docs/ files: Update project references
- Bruno API collection: Update collection name and tests
- Device setup guides: Update all examples
- Implementation plan: Update database schema examples
- README files: Update project references

Part of project rename to Bookhoard.

bruno/sidecar/Get Device Sidecar Config.bru

@@ -15,7 +15,7 @@ get {
 assert {
   response.status == 200
   response.body.version == "1.0"
-  response.body.bookmann exists()
+  response.body.bookhoard exists()
   response.body.books exists()
   response.body.collections exists()
 }