Merge feat/erp-inventar-export: read-only inventory mirror for ERPNext

Brings the ERPNext inventory export (T8) into main after its review:
strict seit format, settle window on the DB clock, BatchMovement
(createdAt, id) index, one scope per new API key and the failed-attempt
lockout on the shared throttler storage. Conflicts resolved in the
permission catalog (System and ERP-Anbindung groups) and ARCHITECTURE.md
(lockout is Annahme 30).

Gates on the merged state: backend lint, typecheck, 1909 unit, 471 e2e,
build, no schema drift; frontend 929 tests, lint, typecheck, build.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Backend/src/auth/permissions/permission-catalog.ts

@@ -370,6 +370,15 @@ export const PERMISSION_CATALOG = [
     ],
     3500,
   ),
+  // Like shop-sync: a narrow read-only allowlist for one machine consumer
+  // (ERPNext's nightly inventory mirror), separate from products:read etc.,
+  // which return descriptions and full records.
+  ...group(
+    'ERP-Anbindung',
+    'erp-inventory',
+    [['read', 'Inventar-Spiegel für ERPNext lesen']],
+    3600,
+  ),
 ] as const satisfies readonly PermissionCatalogEntry[];
 
 export type PermissionKey = (typeof PERMISSION_CATALOG)[number]['key'];