feat(compliance-check): auto-discover missing doc types from homepage

When the user leaves some doc-type rows empty, the tool now actively
searches the website for them — only marks 'not found' as last resort.

Flow:
1. User submits N URLs (e.g. just DSI)
2. For each canonical doc_type with no submitted URL/text, the route
   identifies the most-common base (scheme://netloc) from submitted URLs
3. Calls consent-tester /dsi-discovery on the homepage with
   max_documents=15 (180s timeout)
4. Classifies every discovered doc into a canonical doc_type via
   title/URL keyword rules (_DISCOVERY_RULES — covers cookie/widerruf/
   social_media/agb/nutzungsbedingungen/dsb/impressum/dse)
5. Fills matching empty entries with the discovered text, marks
   auto_discovered=True and discovery_attempted=True

Padding now differentiates:
- 'Auf der Website nicht gefunden' — discovery was attempted, no doc
  matched. Amber badge, friendly hint to add URL manually.
- 'Nicht eingereicht — Quelle nicht angegeben' — user gave NO URLs at
  all, nothing to crawl from. Grey badge.

Email + frontend:
- Status labels: NICHT GEFUNDEN (amber) vs NICHT EINGEREICHT (grey)
- 'Gepruefte Quellen' table tags auto-discovered URLs with a small blue
  'auto-entdeckt' badge so GF sees what tool found vs user submitted.

Implementation only runs when ≥1 URL was submitted (no base to crawl
from otherwise). Adds 30-90s for unsubmitted types but avoids the
'just say nicht gefunden' anti-pattern.

backend-compliance/compliance/api/agent_doc_check_extras.py

@@ -30,15 +30,21 @@ def build_scanned_urls_html(doc_entries: list[dict]) -> str:
         seen.add(url)
         label = _doc_type_label(entry.get("doc_type", ""))
         words = entry.get("word_count") or 0
+        auto = entry.get("auto_discovered")
         try:
             netloc = urlparse(url).netloc.lower().lstrip("www.")
             if netloc:
                 domains.setdefault(netloc, []).append(label)
         except Exception:
             pass
+        badge = ('<span style="display:inline-block;margin-left:6px;'
+                 'background:#dbeafe;color:#1e40af;font-size:10px;'
+                 'padding:1px 6px;border-radius:8px;font-family:sans-serif">'
+                 'auto-entdeckt</span>') if auto else ""
         rows.append(
             f'<tr>'
-            f'<td style="padding:3px 12px 3px 0;color:#475569;font-size:12px">{label}</td>'
+            f'<td style="padding:3px 12px 3px 0;color:#475569;font-size:12px">'
+            f'{label}{badge}</td>'
             f'<td style="padding:3px 12px 3px 0;font-size:12px;'
             f'font-family:ui-monospace,monospace;color:#1e293b;word-break:break-all">'
             f'<a href="{url}" style="color:#2563eb;text-decoration:none">{url}</a></td>'