Add multiple security and validation improvements across the app:
- Prevent session fixation: regenerate session ID on login and after successful 2FA; tighten session cookie params (Secure, HttpOnly, SameSite=Lax).
- Harden installer: add CSRF checks for install/update flows and use PDO::quote when injecting admin credentials into SQL migration to avoid injection; add csrf_field() to installer templates.
- Template hardening: add safe_url and safe_mailto Twig filters, escape tag names for JS, and add rel="noopener noreferrer" to external links to mitigate XSS/opener risks.
- Domain controller: validate referrer to avoid open redirects, enforce user isolation mode when finding/deleting/updating domains and when assigning notification groups (ensures users only affect their own resources).
- Notification groups: verify channel belongs to group before deleting or toggling to prevent unauthorized access.
- ErrorLog: whitelist allowed sort columns to avoid arbitrary column injection in ORDER BY.
- Routes: move the debug whois route to protected/admin area.
These changes collectively reduce attack surface (XSS, open redirect, session fixation, SQL injection) and enforce proper resource isolation and input validation.
Migrate many view templates from raw PHP to Twig and modernize UI/UX for 2FA and settings. Controllers updated to provide avatar data and two-factor info (ProfileController, UserController) and SettingsController now includes timezone lists, notification preset selection, cron path, cached update state and rollback availability. ErrorHandler now attempts to render error pages via a new Core\TwigService with a safe fallback to raw PHP views. TwoFactorService generation silences deprecated warnings during QR code creation. Numerous .php view files were removed and replaced with .twig equivalents (2fa setup/verify/backup-codes and many auth, dashboard, domains, errors, layout, users, tags, tld-registry, etc.), and core/TwigService was added. These changes move the app toward a Twig-based templating system, improve 2FA flows, surface avatar images in lists/profiles, and make error rendering more robust.
