feat: Implemented observability layer and benchmarking

app/clients/exchange_rate_client.py

@@ -4,6 +4,9 @@ from app.core.config import settings
 from app.core.logging import logger
 
 
+from app.core.observability import time_it
+
+
 class ExchangeRateClient:
     def __init__(self):
         self.default_rate = 93.0
@@ -20,6 +23,7 @@ class ExchangeRateClient:
             logger.warning(f"Could not connect to Redis for exchange rate caching: {e}")
             self.redis_client = None
 
+    @time_it("Get USD to INR Exchange Rate")
     async def get_usd_to_inr_rate(self) -> float:
         """
         Retrieves the USD to INR conversion rate.