feat: add policy library with 29 German policy templates

Add 29 new document types (IT security, data, personnel, vendor, BCM
policies) to VALID_DOCUMENT_TYPES and 5 category pills to the document
generator UI. Include seed script for production DB population.

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

backend-compliance/compliance/api/legal_template_routes.py

@@ -58,6 +58,40 @@ VALID_DOCUMENT_TYPES = {
     "incident_response_plan",
     "access_control_concept",
     "risk_management_concept",
+    # Policy templates — IT Security (Migration 054)
+    "information_security_policy",
+    "access_control_policy",
+    "password_policy",
+    "encryption_policy",
+    "logging_policy",
+    "backup_policy",
+    "incident_response_policy",
+    "change_management_policy",
+    "patch_management_policy",
+    "asset_management_policy",
+    "cloud_security_policy",
+    "devsecops_policy",
+    "secrets_management_policy",
+    "vulnerability_management_policy",
+    # Policy templates — Data (Migration 054)
+    "data_protection_policy",
+    "data_classification_policy",
+    "data_retention_policy",
+    "data_transfer_policy",
+    "privacy_incident_policy",
+    # Policy templates — Personnel (Migration 054)
+    "employee_security_policy",
+    "security_awareness_policy",
+    "remote_work_policy",
+    "offboarding_policy",
+    # Policy templates — Vendor/Supply Chain (Migration 054)
+    "vendor_risk_management_policy",
+    "third_party_security_policy",
+    "supplier_security_policy",
+    # Policy templates — BCM (Migration 054)
+    "business_continuity_policy",
+    "disaster_recovery_policy",
+    "crisis_management_policy",
 }
 VALID_STATUSES = {"published", "draft", "archived"}