fix: Eliminate GA false positive + handle short DSI documents

Service detection:
- Only search script tags + src/href attributes for service patterns
- Prevents false positives from DSE text mentioning services
  (e.g. IHK DSE describes etracker, 'google analytics' in text)
- Technical patterns (with regex chars) still checked in full HTML

Short documents:
- Documents with < 200 words flagged as 'Kurzhinweis' instead of
  'MANGELHAFT' — too short for Art. 13 completeness check
- Prevents 96-word navigation pages from showing 8 missing fields

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

backend-compliance/compliance/services/dsi_document_checker.py

@@ -188,6 +188,23 @@ def check_document_completeness(
         })
         return findings
 
+    # Short documents (< 200 words) are likely navigation snippets or
+    # introductory pages, not full Art. 13 documents — flag but don't check
+    word_count = len(text.split())
+    if word_count < 200 and doc_type == "dse":
+        findings.append({
+            "code": f"DSI-SCORE-{doc_type.upper()}",
+            "severity": "LOW",
+            "text": (
+                f"'{doc_title}': Kurzhinweis ({word_count} Woerter) — zu kurz fuer "
+                f"eine vollstaendige Art. 13 DSGVO Pruefung. Kein eigenstaendiges DSI-Dokument."
+            ),
+            "doc_title": doc_title,
+            "doc_url": doc_url,
+            "doc_type": doc_type,
+        })
+        return findings
+
     # Select checklist based on document type
     if doc_type in ("dse", "datenschutz", "privacy"):
         checklist = ART13_CHECKLIST