Fix: Redundanten lokalen Import von find_matching_claim entfernt

Der lokale Import in der Massen-Downgrade-Pruefung ueberschattete den
Top-Level-Import und verursachte: cannot access local variable
find_matching_claim where it is not associated with a value.

Dadurch scheiterte der Faktencheck komplett (0 Faktenchecks).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/agents/orchestrator.py

@@ -1227,7 +1227,6 @@ class AgentOrchestrator:
                 # herabgestuft wuerden, verwerfe die FC-Ergebnisse komplett.
                 established_ids = {ef["id"] for ef in existing_facts if ef.get("status") in ("established", "confirmed")}
                 if established_ids and fact_checks:
-                    from agents.factchecker import find_matching_claim
                     _downgrade_count = 0
                     _remaining_tmp = list(existing_facts)
                     for _fc in fact_checks: