Add Nominatim lookup duration metric

- Added nominatim_lookup_duration Histogram metric to track geocoding API call times
- Integrated metric into processing time breakdown for monitoring
- Tracks only actual Nominatim API calls (cache hits/misses already tracked separately)
- Uses standard buckets (0.01-5.0s) appropriate for network API calls

Author: Agent

fingr/location.py

@@ -11,7 +11,12 @@
 from redis.exceptions import RedisError
 
 from .logging import get_logger
-from .metrics import location_cache_operations, location_resolution_duration, track_time
+from .metrics import (
+    location_cache_operations,
+    location_resolution_duration,
+    nominatim_lookup_duration,
+    track_time,
+)
 
 logger = get_logger(__name__)
 
@@ -62,7 +67,8 @@ def resolve_location(
             return None, None, "No service", False
 
         try:
-            coordinate: Any = geolocator.geocode(data, language="en")
+            with track_time(nominatim_lookup_duration):
+                coordinate: Any = geolocator.geocode(data, language="en")
         except socket.timeout as err:
             logger.warning("Geocoding service timeout", error=str(err))
             return None, None, "No service", False

fingr/metrics.py

@@ -72,6 +72,12 @@
     buckets=(0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1.0),
 )
 
+nominatim_lookup_duration = Histogram(
+    "fingr_nominatim_lookup_duration_seconds",
+    "Nominatim geocoding lookup duration in seconds",
+    buckets=(0.01, 0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0),
+)
+
 
 @contextmanager
 def track_time(histogram: Histogram) -> Generator[None, None, None]: