Qwen3-4B-Thinking-2507-Thinking-Preservation
Derived from Qwen/Qwen3-4B-Thinking-2507. The only change: prior assistant turns keep their <think> reasoning (the stock template strips all but the last).
Thinking is always preserved across multi-turn history (append-only). Every
assistant turn keeps its <think>...</think> reasoning, not just the latest one, and
the generation prompt always opens <think> (passing enable_thinking=False has no
effect). This makes multi-turn agent training match evaluation — the model always
sees its own prior reasoning. Model weights are identical to Qwen/Qwen3-4B-Thinking-2507;
only the chat template differs.