fix: Gemini compressed prompt 키 불일치 및 해외 스캐너 GUBN=0 수정 (#242, #243)

- prompt_optimizer: build_compressed_prompt의 JSON 키를 act/conf/reason에서
  action/confidence/rationale로 수정 (parse_response와 일치시킴)
  → Gemini 응답 100% HOLD로 처리되던 버그 수정
- overseas: fetch_overseas_rankings의 GUBN 파라미터를 1(상승)에서 0(전체)으로 변경
  → 변동성 스캐너가 상승/하락 모두 대상으로 NASDAQ 후보 발견 가능
- test: GUBN==0 검증, build_compressed_prompt 키 이름 검증 추가

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/brain/prompt_optimizer.py

@@ -179,8 +179,8 @@ class PromptOptimizer:
             # Minimal instructions
             prompt = (
                 f"{market_name} trader. Analyze:\n{data_str}\n\n"
-                'Return JSON: {"act":"BUY"|"SELL"|"HOLD","conf":<0-100>,"reason":"<text>"}\n'
-                "Rules: act=BUY/SELL/HOLD, conf=0-100, reason=concise. No markdown."
+                'Return JSON: {"action":"BUY"|"SELL"|"HOLD","confidence":<0-100>,"rationale":"<text>"}\n'
+                "Rules: action=BUY/SELL/HOLD, confidence=0-100, rationale=concise. No markdown."
             )
         else:
             # Data only (for cached contexts where instructions are known)

src/broker/kis_api.py

@@ -430,7 +430,7 @@ class KISBroker:
                 "fid_cond_mrkt_div_code": "J",
                 "fid_cond_scr_div_code": "20170",
                 "fid_input_iscd": "0000",
-                "fid_rank_sort_cls_code": "0000",
+                "fid_rank_sort_cls_code": "0",
                 "fid_input_cnt_1": str(limit),
                 "fid_prc_cls_code": "0",
                 "fid_input_price_1": "0",
@@ -466,7 +466,7 @@ class KISBroker:
             rankings = []
             for item in data.get("output", [])[:limit]:
                 rankings.append({
-                    "stock_code": item.get("mksc_shrn_iscd", ""),
+                    "stock_code": item.get("stck_shrn_iscd") or item.get("mksc_shrn_iscd", ""),
                     "name": item.get("hts_kor_isnm", ""),
                     "price": _safe_float(item.get("stck_prpr", "0")),
                     "volume": _safe_float(item.get("acml_vol", "0")),

src/broker/overseas.py

@@ -133,7 +133,7 @@ class OverseasBroker:
                 "AUTH": "",
                 "EXCD": ranking_excd,
                 "NDAY": "0",
-                "GUBN": "1",
+                "GUBN": "0",  # 0=전체(상승+하락), 1=상승만 — 변동성 스캐너는 전체 필요
                 "VOL_RANG": "0",
             }
 

tests/test_broker.py

@@ -354,6 +354,8 @@ class TestFetchMarketRankings:
         assert "ranking/fluctuation" in url
         assert headers.get("tr_id") == "FHPST01700000"
         assert params.get("fid_cond_scr_div_code") == "20170"
+        # 실전 API는 4자리("0000") 거부 — 1자리("0")여야 한다 (#240)
+        assert params.get("fid_rank_sort_cls_code") == "0"
 
     @pytest.mark.asyncio
     async def test_volume_returns_parsed_rows(self, broker: KISBroker) -> None:
@@ -376,6 +378,27 @@ class TestFetchMarketRankings:
         assert result[0]["price"] == 75000.0
         assert result[0]["change_rate"] == 2.5
 
+    @pytest.mark.asyncio
+    async def test_fluctuation_parses_stck_shrn_iscd(self, broker: KISBroker) -> None:
+        """실전 API는 mksc_shrn_iscd 대신 stck_shrn_iscd를 반환한다 (#240)."""
+        items = [
+            {
+                "stck_shrn_iscd": "015260",
+                "hts_kor_isnm": "에이엔피",
+                "stck_prpr": "794",
+                "acml_vol": "4896196",
+                "prdy_ctrt": "29.74",
+                "vol_inrt": "0",
+            }
+        ]
+        mock_resp = _make_ranking_mock(items)
+        with patch("aiohttp.ClientSession.get", return_value=mock_resp):
+            result = await broker.fetch_market_rankings(ranking_type="fluctuation")
+
+        assert len(result) == 1
+        assert result[0]["stock_code"] == "015260"
+        assert result[0]["change_rate"] == 29.74
+
 
 # ---------------------------------------------------------------------------
 # KRX tick unit / round-down helpers (issue #157)

tests/test_overseas_broker.py

@@ -124,7 +124,7 @@ class TestFetchOverseasRankings:
         assert "/uapi/overseas-stock/v1/ranking/updown-rate" in url
         assert params["EXCD"] == "NAS"
         assert params["NDAY"] == "0"
-        assert params["GUBN"] == "1"
+        assert params["GUBN"] == "0"  # 0=전체(상승+하락), 변동성 스캐너에 필요
         assert params["VOL_RANG"] == "0"
 
         overseas_broker._broker._auth_headers.assert_called_with("HHDFS76290000")

tests/test_token_efficiency.py

@@ -124,6 +124,10 @@ class TestPromptOptimizer:
         assert len(prompt) < 300
         assert "005930" in prompt
         assert "75000" in prompt
+        # Keys must match parse_response expectations (#242)
+        assert '"action"' in prompt
+        assert '"confidence"' in prompt
+        assert '"rationale"' in prompt
 
     def test_build_compressed_prompt_no_instructions(self):
         """Test compressed prompt without instructions."""