fix(plan): NamespacedName digit-start validation BDD scenarios

Remove @tdd_expected_fail tags from the 3 NamespacedName validation
scenarios and fix step mismatch that caused 2 constructor scenarios to
fail. Constructor scenarios now use the existing "a Pydantic
ValidationError should be raised" step (context_strategy_registry_steps)
which correctly checks pydantic.ValidationError instead of the project's
cleveragents.core.exceptions.ValidationError.

Also remove the duplicate @then step accidentally left in
plan_namespaced_name_tdd_steps.py (would have caused NameError since
the `then` import was already removed).

ISSUES CLOSED: #2145, #2147, #8799

CHANGELOG.md

@@ -6,6 +6,7 @@ Changed `wf10_batch.robot` to be less likely to create files, and
 `plan_generation_graph.robot` to give more test answers.
 
 ## [Unreleased]
+- **fix(plan): NamespacedName digit-start validation** (#2145, #2147): `NamespacedName` field validators now reject `namespace` and `name` components whose first character is a digit, raising `pydantic.ValidationError` with message `"must start with a letter"`. BDD constructor scenarios updated to use the `"a Pydantic ValidationError should be raised"` step so the assertion correctly matches the exception type raised by Pydantic model construction.
 - **fix(cli/plan): plan correct JSON output envelope fix and BDD test coverage** (#8584 / PR #8662): Restructured `agents plan correct --format json` output to nest correction fields under `data.correction` (e.g., `data.correction.mode`) and populate the spec-required CLI envelope with `command="plan correct"`, `status`, `exit_code`, `timing`, and `messages` fields. Added three BDD scenarios in `features/tdd_plan_correct_json_output.feature` validating the envelope structure for both revert and append modes.
 - **fix(cli): add --url flag to resource add for git resource type** (#6322): Added support for the `--url` flag on `agents resource add git` command, allowing users to specify a remote URL for git resources. The flag is validated to only apply to git resource types. Includes Behave BDD tests in `features/resource_cli_git_url_flag.feature` and Robot Framework integration tests verifying correct URL validation and CLI behavior.
 - **Session create JSON envelope** (#6441): Fixed `agents session create --format json` returning a flat `data` dict instead of the spec-required nested structure with `data.session`, `data.settings`, and `data.actor_details` sub-objects. The `command` field is now populated correctly. Extended JSON envelope coverage to `agents session list`, `show`, `delete --format json`, `export --output-format json`, and `import --format json` so all session commands emit a structured `messages[].text` field (`"0 sessions listed"`, `"Session details loaded"`, `"Session deleted"`, `"Export completed"`, `"Import completed"`).

features/plan_namespaced_name_validation.feature

@@ -15,13 +15,13 @@ Feature: NamespacedName validation
   @tdd_issue @tdd_issue_2145 @tdd_issue_2147
   Scenario: NamespacedName constructor rejects name starting with a digit
     When I construct a NamespacedName with namespace "local" and name "123-action" expecting an error
-    Then a ValidationError should be raised
+    Then a Pydantic ValidationError should be raised
     And the error message should contain "must start with a letter"
 
   @tdd_issue @tdd_issue_2145 @tdd_issue_2147
   Scenario: NamespacedName constructor rejects namespace starting with a digit
     When I construct a NamespacedName with namespace "999org" and name "valid-name" expecting an error
-    Then a ValidationError should be raised
+    Then a Pydantic ValidationError should be raised
     And the error message should contain "must start with a letter"
 
   # ---------------------------------------------------------------

features/steps/plan_namespaced_name_tdd_steps.py

@@ -49,3 +49,4 @@ def step_when_construct_namespaced_name_expecting_error(
         context.error = e
         context.lsp_error = e
         context.namespaced_name = None
+