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>

.env.example

@@ -74,6 +74,11 @@ LANGGRAPH_URL=
 LANGFLOW_URL=
 LANGFUSE_URL=
 
+# ---------------------------------------------------------------------------
+# Compliance scanner (external tool, opens in new tab) [OPTIONAL]
+# ---------------------------------------------------------------------------
+COMPLIANCE_SCANNER_URL=
+
 # ---------------------------------------------------------------------------
 # Vector database [OPTIONAL]
 # ---------------------------------------------------------------------------