fix(tests): resolve AmbiguousStep collisions in pyyaml_security tests

Three step patterns in pyyaml_security_steps.py clashed with existing
step files, causing all Behave features to error at load time:
- "I call load_yaml_text with YAML text" clashed with actor_config_coverage_boost_steps.py:103
- "the load_yaml_text result should have key" clashed with actor_config_coverage_boost_steps.py:90
- "a ValueError should be raised" clashed with lsp_registry_steps.py:475

Rename all three to unique patterns and update pyyaml_security.feature
to match. Also fix typings/behave/runner.pyi ruff format (.pyi convention:
single blank line before class, no blank lines between stub methods) and
add missing fastapi>=0.100.0 to pyproject.toml (asgi_app.py imports
fastapi but it was absent from declared dependencies, causing typecheck
and integration test failures).

Refs: #9055

features/pyyaml_security.feature

@@ -9,10 +9,10 @@ Feature: PyYAML security constraint
     Then the version should be at least 6.0.3
 
   Scenario: yaml_loader uses safe_load for plain YAML input
-    When I call load_yaml_text with YAML text "provider: anthropic\nmodel: claude-3-5-sonnet\n"
+    When I load the YAML text "provider: anthropic\nmodel: claude-3-5-sonnet\n" using the secure yaml_loader
-    Then the load_yaml_text result should have key "provider" equal to "anthropic"
+    Then the secure yaml_loader result for key "provider" should be "anthropic"
-    And the load_yaml_text result should have key "model" equal to "claude-3-5-sonnet"
+    And the secure yaml_loader result for key "model" should be "claude-3-5-sonnet"
 
   Scenario: yaml_loader rejects YAML with Python object tags
     When I call load_yaml_text with unsafe YAML containing a Python object tag
-    Then a ValueError should be raised
+    Then a pyyaml security ValueError should be raised

features/steps/pyyaml_security_steps.py

@@ -51,7 +51,7 @@ def step_assert_pyyaml_version(context: Context) -> None:
 # ── yaml_loader safe_load enforcement ───────────────────────────────
 
 
-@when('I call load_yaml_text with YAML text "{yaml_text}"')
+@when('I load the YAML text "{yaml_text}" using the secure yaml_loader')
 def step_load_yaml_text(context: Context, yaml_text: str) -> None:
     """Call load_yaml_text with the given YAML text and store the result.
 
@@ -62,7 +62,7 @@ def step_load_yaml_text(context: Context, yaml_text: str) -> None:
     context.load_yaml_result: dict[str, Any] = load_yaml_text(normalised)
 
 
-@then('the load_yaml_text result should have key "{key}" equal to "{value}"')
+@then('the secure yaml_loader result for key "{key}" should be "{value}"')
 def step_assert_yaml_result_key(context: Context, key: str, value: str) -> None:
     """Assert that the parsed YAML result contains the expected key/value pair."""
     result: dict[str, Any] = context.load_yaml_result
@@ -91,7 +91,7 @@ def step_load_unsafe_yaml(context: Context) -> None:
         context.caught_error = exc
 
 
-@then("a ValueError should be raised")
+@then("a pyyaml security ValueError should be raised")
 def step_assert_value_error_raised(context: Context) -> None:
     """Assert that an error was raised when loading unsafe YAML."""
     assert context.caught_error is not None, (

pyproject.toml

@@ -26,6 +26,7 @@ dependencies = [
     # CLI Framework (ADR-009)
     "typer>=0.9.0",
     "uvicorn>=0.30.1",
+    "fastapi>=0.100.0",
     "watchdog>=4.0.0",
     "faiss-cpu>=1.7.4",  # Vector store backend
     "rx>=3.2.0",  # Reactive streams for routing

typings/behave/runner.pyi

@@ -2,7 +2,6 @@
 
 from typing import Any
 
-
 class Context:
     """Behave scenario context object."""