JVNAUTOSCI-1445: move URL extraction requirements into the tool workflow

[witbrock]

Summary

• add a workflow-owned ool_calling.preflight_requirements step before the tool-calling LLM response step
• derive URL extraction requirements from explicit read/extract intent instead of URL presence alone, and thread that policy through routing, llm-step execution, planning, and deterministic retry forcing
• add regression coverage for incidental links, forced URL extraction, workflow structure, and custom tool-pipeline contract matching

Validation

• pdm run pyright src/backend/integrations/internal_mcp/orchestrator.py src/backend/workflows/definitions.py src/backend/workflows/workflow_concept_authority_service.py src/backend/workflows/llm_step_executor.py tests/backend/test_orchestrator_extraction.py tests/backend/test_orchestrator_workflow_selector_routing.py tests/backend/test_turn_execution_workflow_definitions.py
• pdm run pytest tests/backend/test_orchestrator_workflow_selector_routing.py::test_plain_response_overridden_when_prompt_requires_tool_verification tests/backend/test_orchestrator_workflow_selector_routing.py::test_incidental_url_prompt_stays_on_plain_response_path tests/backend/test_orchestrator_workflow_selector_routing.py::test_url_read_prompt_uses_tool_workflow_preflight_and_forces_url_tool -q
• pdm run pytest tests/backend/test_orchestrator_workflow_selector_routing.py::test_custom_tool_pipeline_workflow_dispatches_without_id_special_casing -q
• pdm run pytest tests/backend/test_turn_execution_workflow_definitions.py -q
• pdm run pytest tests/backend/test_orchestrator_extraction.py::test_derive_prompt_tool_requirements_adds_url_extraction_tool_for_current_prompt -q
• pdm run pytest tests/backend/test_orchestrator_extraction.py::test_derive_prompt_tool_requirements_ignores_incidental_urls_without_read_intent -q
• pdm run pytest tests/backend/test_orchestrator_extraction.py::test_infer_required_prompt_tool_retry_tool_calls_forces_url_extraction -q
• pdm run pytest tests/backend/test_workflow_concept_authority_service.py::test_bootstrap_publishes_canonical_chat_graphs_with_loader_runtime_parity -q

Notes

• pdm run pytest tests -m lane_backend_workflows -q and pdm run pytest tests -m lane_backend_mcp -q were both attempted but exceeded the 5 minute command timeout in this environment.