fix(cross-doc): suppress false positives when regex checks already pass

Cross-search "not in text" findings are only shown when regex L1
completeness < 50%. This prevents false positives where the text IS
the right doc_type but doesn't contain the specific cross-search
keywords (e.g. Impressum passes 9/13 checks but lacks "§5 TMG").

Also: cross-search now checks entries with wrong text, not just empty.

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

backend-compliance/compliance/api/agent_compliance_check_routes.py

@@ -237,7 +237,10 @@ async def _run_compliance_check(check_id: str, req: ComplianceCheckRequest):
             # Apply profile context filter
             result = _apply_profile_filter(result, profile, doc_type)
 
-            # Add placement findings (doc found in wrong location)
+            # Add placement findings — but only if the regex checks confirm
+            # the text doesn't match. If completeness >= 50%, the text IS the
+            # right doc_type despite missing cross-search keywords.
+            if result.completeness_pct < 50:
                 for pf in placement_findings:
                     if pf.get("doc_type") == doc_type:
                         result.checks.insert(0, CheckItem(**{