feat: add 67 new endpoints across 10 feature groups

Prerequisite refactor:
- Consolidate duplicate _to_dicts into shared obb_utils.to_list
- Add fetch_historical and first_or_empty helpers to obb_utils

Phase 1 - Local computation (no provider risk):
- Group I: 12 technical indicators (ATR, ADX, Stoch, OBV, Ichimoku,
  Donchian, Aroon, CCI, Keltner, Fibonacci, A/D, Volatility Cones)
- Group J: Sortino, Omega ratios + rolling stats (variance, stdev,
  mean, skew, kurtosis, quantile via generic endpoint)
- Group H: ECB currency reference rates

Phase 2 - FRED/Federal Reserve providers:
- Group C: 10 fixed income endpoints (treasury rates, yield curve,
  auctions, TIPS, EFFR, SOFR, HQM, commercial paper, spot rates,
  spreads)
- Group D: 11 economy endpoints (CPI, GDP, unemployment, PCE, money
  measures, CLI, HPI, FRED search, balance of payments, Fed holdings,
  FOMC documents)
- Group E: 5 survey endpoints (Michigan, SLOOS, NFP, Empire State,
  BLS search)

Phase 3 - SEC/stockgrid/FINRA providers:
- Group B: 4 equity fundamental endpoints (management, dividends,
  SEC filings, company search)
- Group A: 4 shorts/dark pool endpoints (short volume, FTD, short
  interest, OTC dark pool)
- Group F: 3 index/ETF enhanced (S&P 500 multiples, index
  constituents, ETF N-PORT)

Phase 4 - Regulators:
- Group G: 5 regulatory endpoints (COT report, COT search, SEC
  litigation, institution search, CIK mapping)

Security hardening:
- Service-layer allowlists for all getattr dynamic dispatch
- Regex validation on date, country, security_type, form_type params
- Exception handling in fetch_historical
- Callable guard on rolling stat dispatch

Total: 32 existing + 67 new = 99 endpoints, all free providers.

macro_service.py

@@ -6,6 +6,8 @@ from typing import Any
 
 from openbb import obb
 
+from obb_utils import to_list
+
 logger = logging.getLogger(__name__)
 
 PROVIDER = "fred"
@@ -23,19 +25,6 @@ SERIES = {
 }
 
 
-def _to_dicts(result: Any) -> list[dict[str, Any]]:
-    if result is None or result.results is None:
-        return []
-    if isinstance(result.results, list):
-        return [
-            item.model_dump() if hasattr(item, "model_dump") else vars(item)
-            for item in result.results
-        ]
-    if hasattr(result.results, "model_dump"):
-        return [result.results.model_dump()]
-    return [vars(result.results)]
-
-
 async def get_series(
     series_id: str, limit: int = 10, latest: bool = False,
 ) -> list[dict[str, Any]]:
@@ -52,7 +41,7 @@ async def get_series(
             obb.economy.fred_series,
             **kwargs,
         )
-        items = _to_dicts(result)
+        items = to_list(result)
         items = [
             {**item, "date": str(item["date"])}
             if "date" in item and not isinstance(item["date"], str)