fix(llm): route harmony thinking streams (#2449)

tests/test_llm_core_reasoning.py

@@ -172,3 +172,37 @@ def test_registered_thinking_model_stray_close_tag_repair_unchanged(monkeypatch)
     assert deltas, deltas
     first = deltas[0]["delta"]
     assert first.startswith("<think>"), f"expected repair prefix, got: {first!r}"
+
+
+def test_thinking_field_emits_thinking_chunk(monkeypatch):
+    deltas = _run_stream(
+        "gpt-oss:20b",
+        [
+            'data: {"choices":[{"delta":{"thinking":"checking files"}}]}',
+            'data: {"choices":[{"delta":{"content":"visible answer"}}]}',
+            "data: [DONE]",
+        ],
+        monkeypatch,
+    )
+    assert any(d.get("thinking") and d["delta"] == "checking files" for d in deltas), deltas
+    assert any((not d.get("thinking")) and d["delta"] == "visible answer" for d in deltas), deltas
+
+def test_harmony_analysis_channel_routes_to_thinking(monkeypatch):
+    deltas = _run_stream(
+        "gpt-oss:20b",
+        [
+            'data: {"choices":[{"delta":{"content":"<|channel|>ana"}}]}',
+            'data: {"choices":[{"delta":{"content":"lysis<|message|>We need to inspect."}}]}',
+            'data: {"choices":[{"delta":{"content":"<|end|><|channel|>final<|message|>Here "}}]}',
+            'data: {"choices":[{"delta":{"content":"are the files.<|end|>"}}]}',
+            "data: [DONE]",
+        ],
+        monkeypatch,
+    )
+    thinking = "".join(d["delta"] for d in deltas if d.get("thinking"))
+    answer = "".join(d["delta"] for d in deltas if not d.get("thinking"))
+
+    assert thinking == "We need to inspect."
+    assert answer == "Here are the files."
+    assert "<|channel|>" not in thinking + answer
+    assert "<|message|>" not in thinking + answer