fix(core): recover from hallucinated tool names instead of ending the scan

A tool call for a name Strix does not register raised ModelBehaviorError
from the SDK turn resolver, which nothing retries: the root agent's raise
tore down the whole scan and a sub-agent died before its status was set.
Opt into the SDK's tool_not_found_behavior="return_error_to_model" so the
unknown call comes back as a tool result and the agent self-corrects.

The setting landed in openai-agents 0.19.0, which requires openai>=2.45,
so both pins move.

pyproject.toml

@@ -33,8 +33,8 @@ classifiers = [
   "Programming Language :: Python :: 3.14",
 ]
 dependencies = [
-  "openai-agents[litellm]==0.14.6",
-  "openai>=2.26.0,<2.45",
+  "openai-agents[litellm]>=0.19.0,<0.20",
+  "openai>=2.45.0,<3",
   "litellm",
   "pydantic>=2.11.3",
   "pydantic-settings>=2.13.0",
@@ -233,6 +233,7 @@ ignore = [
 "strix/interface/auth_cli.py" = ["N802"]
 "tests/test_codex_streaming.py" = ["N802"]
 "tests/test_disable_streaming.py" = ["N802"]
+"tests/test_unknown_tool_recovery.py" = ["N802"]
 "tests/test_report_pdf.py" = ["S105", "S106"]
 # Stdlib HTTP handler overrides (do_GET/do_POST) and lazy imports that avoid a
 # circular dependency with strix.telemetry / strix.interface.viewer.report_pdf.