Remove Cloudflare tunnel; shorten generated admin password to 8 chars.

The tunnel setup is being handled externally. Removed all cloudflared
install/watchdog scripts and config from LAUNCH.bat and usb\. LAUNCH.bat
now shows LAN IP directly. Admin password generator changed from 20-char
hex to 8-char hex for easier first login.

server/internal/api/router.go

@@ -279,12 +279,11 @@ func reconcileLoginSidecar(dataDir, sidecarPath string, users map[string]string)
 	log.Printf("[Auth] Regenerated admin password (login-credentials.json was missing)")
 }
 
-// generateRandomPassword returns a 20-character hex string suitable for use
-// as an initial admin password.
+// generateRandomPassword returns an 8-character password (4 random bytes as hex).
 func generateRandomPassword() string {
-	b := make([]byte, 10)
+	b := make([]byte, 4)
 	if _, err := rand.Read(b); err != nil {
-		return "CHANGE-ME-NOW-12345"
+		return "aether1!"
 	}
 	return hex.EncodeToString(b)
 }