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/api/connect/route.ts

@@ -51,7 +51,7 @@ export async function POST(request: NextRequest) {
     .set({ usedAt: new Date(), usedBy: session.user.id, isActive: false })
     .where(eq(sessionCodes.id, sessionCode.id))
 
-  // Create session record
+  // Create session record (viewer_token is auto-generated by DB default)
   const newSession = await db
     .insert(sessions)
     .values({
@@ -61,7 +61,11 @@ export async function POST(request: NextRequest) {
       connectionType: 'session_code',
       sessionCode: normalizedCode,
     })
-    .returning({ id: sessions.id })
+    .returning({ id: sessions.id, viewerToken: sessions.viewerToken })
 
-  return NextResponse.json({ sessionId: newSession[0].id })
+  return NextResponse.json({
+    sessionId: newSession[0].id,
+    viewerToken: newSession[0].viewerToken,
+    machineId: sessionCode.machineId,
+  })
 }