Adds CustomerRepository::findDuplicate() which checks for an existing
  record with the same customer_type_id and attribute_values before any
  write. The update path excludes the current record so saving without
  changes does not trigger a false positive. Both the create and edit
  forms now display a linked error banner identifying the conflicting
  customer by ID and type name.

Job type attributes now support a "Customer Type" pseudo-type: selecting
a customer type expands its attribute definitions inline as real rows,
letting job types reuse field configurations without manual re-entry.
The "customer" placeholder type is stripped server-side before persisting.

Also update production Keycloak redirect URIs from IP to hostname and
ignore .claude/ and .abacusai/ tool directories.