feat: OpenBB Investment Analysis API

REST API wrapping OpenBB SDK for stock data, sentiment analysis,
technical indicators, macro data, and rule-based portfolio analysis.

- Stock data via yfinance (quote, profile, metrics, financials, historical, news)
- News sentiment via Alpha Vantage (per-article, per-ticker scores)
- Analyst data via Finnhub (recommendations, insider trades, upgrades)
- Macro data via FRED (Fed rate, CPI, GDP, unemployment, treasury yields)
- Technical indicators via openbb-technical (RSI, MACD, SMA, EMA, Bollinger)
- Rule-based portfolio analysis engine (BUY_MORE/HOLD/SELL)
- Stock discovery (gainers, losers, active, undervalued, growth)
- 102 tests, all passing

tests/test_openbb_service.py

@@ -0,0 +1,47 @@
+from openbb_service import _to_dicts, _first_or_empty
+
+
+class MockModel:
+    def __init__(self, data: dict):
+        self._data = data
+
+    def model_dump(self):
+        return self._data
+
+
+class MockOBBject:
+    def __init__(self, results):
+        self.results = results
+
+
+class TestToDicts:
+    def test_none_result(self):
+        assert _to_dicts(None) == []
+
+    def test_none_results(self):
+        obj = MockOBBject(results=None)
+        assert _to_dicts(obj) == []
+
+    def test_list_results(self):
+        obj = MockOBBject(results=[
+            MockModel({"a": 1}),
+            MockModel({"b": 2}),
+        ])
+        result = _to_dicts(obj)
+        assert len(result) == 2
+        assert result[0] == {"a": 1}
+
+    def test_single_result(self):
+        obj = MockOBBject(results=MockModel({"x": 42}))
+        result = _to_dicts(obj)
+        assert result == [{"x": 42}]
+
+
+class TestFirstOrEmpty:
+    def test_empty(self):
+        assert _first_or_empty(None) == {}
+
+    def test_with_data(self):
+        obj = MockOBBject(results=[MockModel({"price": 150.0})])
+        result = _first_or_empty(obj)
+        assert result == {"price": 150.0}