fix(infra): handle database deduplication unique constraints in db buffer

- Intercepts psycopg2 UniqueViolation exceptions on the ene_pkg_hash_idx
  unique index constraint.
- Logs duplicate content violations as successful deduplication skips
  instead of triggering transaction retries and fallback logging.

Build: 0 jobs, 0 errors (lake build)

4-Infrastructure/shim/rrc_bosonic_db_buffer.py

@@ -259,6 +259,10 @@ class AsyncDatabaseBuffer:
             self.conn.commit()
         except Exception as e:
             self.conn.rollback()
+            # Catch duplicate content hash violations and skip them cleanly as successful dedups
+            if e.__class__.__name__ == "UniqueViolation" and "ene_pkg_hash_idx" in str(e):
+                log.info("Deduplication filter triggered: record with identical content_hash already exists. Skipping.")
+                return
             raise e
         finally:
             cur.close()