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/Backend/.env

@@ -1,6 +1,7 @@
 NODE_ENV="development"
 HOST=0.0.0.0
 PORT=5000
+CLOUDFLARE_HOST=communitydentistsoflowell.mydentalofficemanagement.com
 FRONTEND_URLS=http://localhost:3000,http://communitydentistsoflowell.mydentalofficemanagement.com,https://communitydentistsoflowell.mydentalofficemanagement.com
 SELENIUM_AGENT_BASE_URL=http://localhost:5002
 JWT_SECRET = 'dentalsecret'
@@ -8,4 +9,5 @@ DB_HOST=localhost
 DB_USER=postgres
 DB_PASSWORD=mypassword
 DB_NAME=dentalapp
-DATABASE_URL=postgresql://postgres:mypassword@localhost:5432/dentalapp
+DATABASE_URL=postgresql://postgres:mypassword@localhost:5432/dentalapp
+LICENSE_SECRET=3aa4ab937e46c6863b9e3c2b591a595b31ea3af1060bf5e7961ad722a8b54f92

apps/Backend/src/routes/index.ts

@@ -39,6 +39,7 @@ import insuranceContactsRoutes from "./insurance-contacts";
 import commissionsRoutes from "./commissions";
 import shoppingVendorsRoutes from "./shopping-vendors";
 import feeScheduleRoutes from "./feeSchedule";
+import licenseRoutes from "./license";
 
 const router = Router();
 
@@ -82,5 +83,6 @@ router.use("/insurance-contacts", insuranceContactsRoutes);
 router.use("/commissions", commissionsRoutes);
 router.use("/shopping-vendors", shoppingVendorsRoutes);
 router.use("/fee-schedule", feeScheduleRoutes);
+router.use("/license", licenseRoutes);
 
 export default router;

apps/Backend/src/routes/license.ts

@@ -0,0 +1,97 @@
+import { Router } from "express";
+import crypto from "crypto";
+import fs from "fs";
+import path from "path";
+
+const router = Router();
+
+const LICENSE_FILE = path.join(process.cwd(), "license.json");
+const SECRET = process.env.LICENSE_SECRET || "";
+
+function validateKey(key: string): { valid: boolean; expiry?: string; error?: string } {
+  // Format: DENTAL-{24-char-signature}-{YYYY-MM-DD}
+  const parts = key.trim().split("-");
+  if (parts.length !== 6 || parts[0] !== "DENTAL") {
+    return { valid: false, error: "Invalid license key format" };
+  }
+
+  const signature = parts[1];
+  const expiryStr = `${parts[2]}-${parts[3]}-${parts[4]}`;
+
+  // Verify signature
+  const payload = `DENTAL:${expiryStr}`;
+  const expectedSig = crypto
+    .createHmac("sha256", SECRET)
+    .update(payload)
+    .digest("hex")
+    .substring(0, 24)
+    .toUpperCase();
+
+  if (signature !== expectedSig) {
+    return { valid: false, error: "Invalid license key" };
+  }
+
+  // Check expiry
+  const expiry = new Date(expiryStr);
+  if (isNaN(expiry.getTime())) {
+    return { valid: false, error: "Invalid expiry date in key" };
+  }
+
+  if (new Date() > expiry) {
+    return { valid: false, expiry: expiryStr, error: "License key has expired" };
+  }
+
+  return { valid: true, expiry: expiryStr };
+}
+
+function loadLicense(): { key: string; expiry: string } | null {
+  try {
+    if (!fs.existsSync(LICENSE_FILE)) return null;
+    return JSON.parse(fs.readFileSync(LICENSE_FILE, "utf8"));
+  } catch {
+    return null;
+  }
+}
+
+function saveLicense(key: string, expiry: string) {
+  fs.writeFileSync(LICENSE_FILE, JSON.stringify({ key, expiry }, null, 2));
+}
+
+// GET /api/license/status
+router.get("/status", (req, res) => {
+  const stored = loadLicense();
+  if (!stored) {
+    return res.json({ activated: false, expired: false, expiry: null, daysLeft: null });
+  }
+
+  const result = validateKey(stored.key);
+  if (!result.valid && result.expiry) {
+    return res.json({ activated: true, expired: true, expiry: stored.expiry, daysLeft: 0 });
+  }
+  if (!result.valid) {
+    return res.json({ activated: false, expired: false, expiry: null, daysLeft: null });
+  }
+
+  const expiry = new Date(stored.expiry);
+  const daysLeft = Math.ceil((expiry.getTime() - Date.now()) / (1000 * 60 * 60 * 24));
+
+  return res.json({ activated: true, expired: false, expiry: stored.expiry, daysLeft });
+});
+
+// POST /api/license/activate
+router.post("/activate", (req, res) => {
+  const { key } = req.body;
+  if (!key) {
+    return res.status(400).json({ error: "License key is required" });
+  }
+
+  const result = validateKey(key);
+  if (!result.valid) {
+    return res.status(400).json({ error: result.error });
+  }
+
+  saveLicense(key.trim(), result.expiry!);
+  return res.json({ success: true, expiry: result.expiry });
+});
+
+export default router;