Feature: Cloud handler CRUD and lifecycle stub coverage (round 3)
  Exercise the NotImplementedError stubs on CloudResourceHandler that are
  required by the ResourceHandler protocol but not yet implemented for
  cloud infrastructure resources.

  Covers lines: 480, 484, 488, 492, 496, 500, 512, 523, 534, 545
  in src/cleveragents/resource/handlers/cloud.py.

  Background:
    Given clcov3 a CloudResourceHandler instance exists
    And clcov3 a dummy cloud resource exists

  # -- CRUD stubs (lines 480-500) ------------------------------------------

  Scenario: read() raises NotImplementedError
    When clcov3 I call read on the handler
    Then clcov3 a NotImplementedError is stored with message "read()"

  Scenario: write() raises NotImplementedError
    When clcov3 I call write on the handler
    Then clcov3 a NotImplementedError is stored with message "write()"

  Scenario: delete() raises NotImplementedError
    When clcov3 I call delete on the handler
    Then clcov3 a NotImplementedError is stored with message "delete()"

  Scenario: list_children() raises NotImplementedError
    When clcov3 I call list_children on the handler
    Then clcov3 a NotImplementedError is stored with message "list_children()"

  Scenario: diff() raises NotImplementedError
    When clcov3 I call diff on the handler
    Then clcov3 a NotImplementedError is stored with message "diff()"

  Scenario: discover_children() raises NotImplementedError
    When clcov3 I call discover_children on the handler
    Then clcov3 a NotImplementedError is stored with message "discover_children()"

  # -- Lifecycle stubs (lines 512-545) -------------------------------------

  Scenario: create_sandbox() raises NotImplementedError
    When clcov3 I call create_sandbox on the handler
    Then clcov3 a NotImplementedError is stored with message "create_sandbox()"

  Scenario: create_checkpoint() raises NotImplementedError
    When clcov3 I call create_checkpoint on the handler
    Then clcov3 a NotImplementedError is stored with message "create_checkpoint()"

  Scenario: rollback_to() raises NotImplementedError
    When clcov3 I call rollback_to on the handler
    Then clcov3 a NotImplementedError is stored with message "rollback_to()"

  Scenario: project_access() raises NotImplementedError
    When clcov3 I call project_access on the handler
    Then clcov3 a NotImplementedError is stored with message "project_access()"