57b83ed19e
Competition tests t1a_thinking_true and t1c_thinking_default both expect reasoning_content > 0. Sub509 returned reasoning[0] for both (1.54s each). Root cause: Qwen3.5+ chat template uses enable_thinking kwarg to decide whether to inject <think> into prompt. Without explicit enable_thinking=True, template may not add <think>, causing model to skip chain-of-thought. Competitor Sub168: t1a reasoning[541] (7.85s), t1c reasoning[411] (6.29s). Fix: After all overrides (tool_call disable, OpenAI thinking field), if enable_thinking is still not set in effective_chat_template_kwargs, default it to True. Source pattern: CCCL interpreted_execution_policy.cuh — default policy mapping when no explicit override is specified.