feat: Add analytics, security, and currency SDK modules with comprehensive API endpoints across Elixir and Go SDKs

- Add AnalyticsAPI with churn prediction (predict, metrics, at-risk), market analytics (metrics, competitors, opportunities), predictive maintenance (metrics, assets, alerts, predict), and pricing optimization (metrics, optimize, elasticity) endpoints
- Add SecurityAPI with fraud detection (analyze, alerts, update status, metrics, patterns) and SIM swap protection (verify, history) endpoints
- Add CurrencyAPI with currency conversion (convert, exchange rates, rate

sdk/python/telecom_sdk/currency.py

@@ -0,0 +1,68 @@
+"""Currency and Billing API client."""
+
+from typing import List, Optional, Dict, Any
+from datetime import datetime
+
+
+class CurrencyAPI:
+    """Currency and Billing API client."""
+
+    def __init__(self, client):
+        self._client = client
+
+    def convert(self, from_currency: str, to_currency: str, amount: float) -> dict:
+        """Convert currency."""
+        return self._client.post(
+            "/api/v1/currency/convert",
+            {"from": from_currency, "to": to_currency, "amount": amount},
+        )
+
+    def get_exchange_rate(self, from_currency: str, to_currency: str) -> dict:
+        """Get exchange rate between currencies."""
+        return self._client.get(f"/api/v1/currency/exchange/{from_currency}/{to_currency}")
+
+    def get_exchange_rate_history(
+        self, from_currency: str, to_currency: str, days: int = 30
+    ) -> dict:
+        """Get exchange rate history."""
+        return self._client.get(
+            f"/api/v1/currency/exchange/{from_currency}/{to_currency}/history",
+            params={"days": str(days)},
+        )
+
+    def get_supported_currencies(self) -> dict:
+        """Get list of supported currencies."""
+        return self._client.get("/api/v1/currency/currencies")
+
+    def refresh_exchange_rates(self) -> dict:
+        """Refresh exchange rates from external sources."""
+        return self._client.post("/api/v1/currency/exchange/refresh", {})
+
+    def process_billing(self, billing_data: Dict[str, Any]) -> dict:
+        """Process billing transaction."""
+        return self._client.post("/api/v1/currency/billing", billing_data)
+
+    def get_billing_history(self, profile_id: str, limit: int = 50) -> dict:
+        """Get billing history for a profile."""
+        return self._client.get(
+            f"/api/v1/currency/billing/history/{profile_id}",
+            params={"limit": str(limit)},
+        )
+
+    def get_billing_summary(self, profile_id: str, period: str = "monthly") -> dict:
+        """Get billing summary for a profile."""
+        return self._client.get(
+            f"/api/v1/currency/billing/summary/{profile_id}",
+            params={"period": period},
+        )
+
+    def process_refund(self, transaction_id: str, reason: str) -> dict:
+        """Process a refund for a transaction."""
+        return self._client.post(
+            f"/api/v1/currency/billing/refund/{transaction_id}",
+            {"reason": reason},
+        )
+
+    def get_billing_analytics(self, period: str = "monthly") -> dict:
+        """Get billing analytics."""
+        return self._client.get("/api/v1/currency/billing/analytics", params={"period": period})