fix: resolve curl_cffi TLS errors and fix FRED/upgrades endpoints

- Pin curl_cffi==0.7.4 to avoid BoringSSL bug in 0.12-0.14
- Patch curl_cffi Session to use safari TLS fingerprint instead of
  chrome, which triggers SSL_ERROR_SYSCALL on some networks
- Register FRED API key with OpenBB credentials at startup
- Fix macro overview to return latest data instead of oldest, and
  extract values by FRED series ID key
- Replace Finnhub upgrades endpoint (premium-only) with yfinance
  upgrades_downgrades which includes price target changes
- Remove redundant curl_cffi upgrade from Dockerfile

pyproject.toml

@@ -9,6 +9,7 @@ dependencies = [
     "openbb[yfinance]",
     "pydantic-settings",
     "httpx",
+    "curl_cffi==0.7.4",
 ]
 
 [project.optional-dependencies]