feat(company): add subscription expiry management and expired company guard

Add validity period fields to company CRUD, display expiry info in
table and profile, and block access for expired companies via a
full-screen guard component.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/services/api/api.ts

@@ -83,6 +83,8 @@ export async function companyHandle(
     name?: string;
     email?: string;
     status?: number;
+    validityStartTime?: string | null;
+    validityEndTime?: string | null;
   },
   options?: ObjType,
 ) {