feat(sidebar): add compliance scanner link from env config

Read COMPLIANCE_SCANNER_URL from environment via ServiceUrls config and
surface it through AuthInfo to the sidebar. The link renders with a
shield icon and opens in a new tab, only when the URL is configured.
Includes i18n translations for all five locales.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

assets/i18n/de.json

@@ -46,7 +46,8 @@
     "agents": "Agenten",
     "flow": "Flow",
     "analytics": "Analytics",
-    "pricing": "Preise"
+    "pricing": "Preise",
+    "compliance": "Compliance"
   },
   "auth": {
     "redirecting_login": "Weiterleitung zur Anmeldung...",