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

config.py

@@ -0,0 +1,20 @@
+from pydantic import Field
+from pydantic_settings import BaseSettings
+
+
+class Settings(BaseSettings):
+    host: str = "0.0.0.0"
+    port: int = 8000
+    cors_origins: list[str] = Field(default_factory=lambda: ["http://localhost:3000"])
+    log_level: str = "info"
+    debug: bool = False
+
+    # Optional API keys (free tiers)
+    finnhub_api_key: str = ""
+    fred_api_key: str = ""
+    alphavantage_api_key: str = ""
+
+    model_config = {"env_prefix": "INVEST_API_", "env_file": ".env"}
+
+
+settings = Settings()