Ship Novya PWA with backend for deployable production use.

Fix production TypeScript builds and add DEPLOY.md so the app can be hosted from this repo.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/shared/constants/app.ts

@@ -0,0 +1,25 @@
+export const APP_NAME = 'Novya API';
+export const APP_DESCRIPTION = 'Novya learning platform backend API';
+
+/** Minimum wait after completing session N before session N+1 unlocks. Set to 0 to disable cooldown (dev/testing). */
+export const SESSION_UNLOCK_INTERVAL_MS = 0;
+
+export const DEFAULT_PAGE = 1;
+export const DEFAULT_PAGE_SIZE = 20;
+export const MAX_PAGE_SIZE = 100;
+
+export const REQUEST_ID_HEADER = 'x-request-id';
+
+export const SENSITIVE_FIELD_PATTERNS = [
+  /password/i,
+  /otp/i,
+  /token/i,
+  /jwt/i,
+  /api[_-]?key/i,
+  /authorization/i,
+  /secret/i,
+  /prompt/i,
+  /refresh[_-]?token/i,
+  /answer/i,
+  /content/i,
+] as const;