Add Python agent, WebSocket relay, real viewer, enrollment tokens

- WebSocket relay service (FastAPI) bridges agents and viewers
- Python agent with screen capture (mss), input control (pynput),
  script execution, and auto-reconnect
- Windows service wrapper, PyInstaller spec, NSIS installer for
  silent mass deployment (RemoteLink-Setup.exe /S /SERVER= /ENROLL=)
- Enrollment token system: admin generates tokens, agents self-register
- Real WebSocket viewer replaces simulated canvas
- Linux agent binary served from /downloads/remotelink-agent-linux
- DB migration 0002: viewer_token on sessions, enrollment_tokens table
- Sign-up pages cleaned up (invite-only redirect)

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

app/auth/sign-up-success/page.tsx

@@ -20,15 +20,15 @@ export default function SignUpSuccessPage() {
               <div className="mx-auto mb-4 flex h-16 w-16 items-center justify-center rounded-full bg-primary/10">
                 <Mail className="h-8 w-8 text-primary" />
               </div>
-              <CardTitle className="text-2xl">Check your email</CardTitle>
+              <CardTitle className="text-2xl">Account created</CardTitle>
               <CardDescription className="text-balance">
-                {"We've sent you a confirmation link. Please check your inbox and click the link to activate your account."}
+                Your account has been set up. You can now sign in.
               </CardDescription>
             </CardHeader>
             <CardContent className="space-y-4">
               <div className="rounded-lg bg-muted/50 p-4 text-sm text-muted-foreground">
                 <p className="text-balance">
-                  {"Didn't receive the email? Check your spam folder or try signing up again with a different email address."}
+                  Use the email address from your invite link to log in.
                 </p>
               </div>
               <Button asChild className="w-full">