feat: add license activation system with feature gates

- License key generator tool at ~/Desktop/LicenseGenerator
- Backend validator route (GET /api/license/status, POST /api/license/activate)
- Activation page in sidebar with status, key input, and free/premium feature list
- useLicense hook for frontend license state
- Feature gates: premium eligibility buttons (DDMA, DeltaIns, Tufts, United, CCA) disabled without license
- Feature gates: premium claim buttons (CCA, Delta MA, United, Tufts) and all PreAuth buttons disabled without license
- Free features always active: MassHealth eligibility/claim, Documents, Payments, Backups, Reports
- README: license key generator usage instructions

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

apps/Frontend/src/App.tsx

@@ -31,6 +31,7 @@ const JobMonitorPage = lazy(() => import("./pages/job-monitor-page"));
 const ChartPage = lazy(() => import("./pages/chart-page"));
 const DentalShoppingSearchTagPage = lazy(() => import("./pages/dental-shopping-search-tag-page"));
 const DentalShoppingLoginInfoPage = lazy(() => import("./pages/dental-shopping-login-info-page"));
+const ActivationPage = lazy(() => import("./pages/activation-page"));
 const NotFound = lazy(() => import("./pages/not-found"));
 
 function Router() {
@@ -65,6 +66,7 @@ function Router() {
       <ProtectedRoute path="/cloud-storage" component={() => <CloudStoragePage />} />
       <ProtectedRoute path="/dental-shopping/search-tag" component={() => <DentalShoppingSearchTagPage />} />
       <ProtectedRoute path="/dental-shopping/login-info" component={() => <DentalShoppingLoginInfoPage />} />
+      <ProtectedRoute path="/activation" component={() => <ActivationPage />} adminOnly />
       <ProtectedRoute
         path="/job-monitor"
         component={() => <JobMonitorPage />}