fix: complete exception logging in publish_amqp

Replace logger.error() calls with logger.exception() to capture full stack
traces in production Kubernetes logs. Adds structured context via extra={}
for improved observability:
- load_payload: Include file path on FileNotFoundError/JSONDecodeError
- format_routing_key: Show template and available fields on KeyError
- main: Include exchange/routing_key/host on publish failure

Closes phase3-analysis #1 (error logging completion)

Author: wietzesuijker

scripts/publish_amqp.py

@@ -27,10 +27,10 @@ def load_payload(payload_file: Path) -> dict[str, Any]:
         data: dict[str, Any] = json.loads(payload_file.read_text())
         return data
     except FileNotFoundError:
-        logger.error("Payload file not found: %s", payload_file)
+        logger.exception("Payload file not found", extra={"file": str(payload_file)})
         sys.exit(1)
-    except json.JSONDecodeError as e:
-        logger.error("Invalid JSON in payload file: %s", e)
+    except json.JSONDecodeError:
+        logger.exception("Invalid JSON in payload file", extra={"file": str(payload_file)})
         sys.exit(1)
 
 
@@ -41,8 +41,11 @@ def format_routing_key(template: str, payload: dict[str, Any]) -> str:
     """
     try:
         return template.format(**payload)
-    except KeyError as e:
-        logger.error("Missing field %s in payload for routing key template", e)
+    except KeyError:
+        logger.exception(
+            "Missing required field in payload for routing key template",
+            extra={"template": template, "available_fields": list(payload.keys())},
+        )
         sys.exit(1)
 
 
@@ -124,8 +127,15 @@ def main() -> None:
             payload=payload,
             virtual_host=args.virtual_host,
         )
-    except Exception as e:
-        logger.error("Failed to publish message: %s", e)
+    except Exception:
+        logger.exception(
+            "Failed to publish AMQP message",
+            extra={
+                "exchange": args.exchange,
+                "routing_key": routing_key,
+                "host": args.host,
+            },
+        )
         sys.exit(1)