docs(P07): complete swallowed-error-hardening phase (v1.13.10)

---ci---
project: acdl
phase: 7
milestone: v1.14
status: complete
requirements:
  covered: [REQ-141]
  partial: []
---/ci---

core/lambda/contract_ingestor.py

@@ -17,6 +17,7 @@ requests. The invoke policy is scoped via ABAC (consumer repo identity).
 import datetime
 import json
 import os
+import urllib.error
 import urllib.parse
 
 import boto3
@@ -154,7 +155,16 @@ def _report_error(payload):
         with urllib.request.urlopen(req, timeout=10) as resp:
             search_result = json.loads(resp.read())
         existing = search_result.get("items", [])
-    except Exception:
+    except urllib.error.HTTPError as e:
+        if e.code == 404:
+            existing = []
+        else:
+            import sys
+            print(f"WARNING: GitHub issue search failed (HTTP {e.code}): {e}", file=sys.stderr)
+            existing = []
+    except urllib.error.URLError as e:
+        import sys
+        print(f"WARNING: GitHub issue search network error: {e}", file=sys.stderr)
         existing = []
 
     body = f"""## Deploy Failure Report