feat(sshd-setup): multi-distro support and verification steps

- sshd-setup.sh: Auto-detect OS (Debian/Ubuntu/Fedora/RHEL/CentOS)
- Use appropriate package manager (apt-get vs dnf)
- Add verification steps after each major phase
- Exit with error if sshd installation fails
- Exit with error if sshd doesn't start successfully
- Add troubleshooting section in output

- kugetsu-install.sh: Add verification that kugetsu binary exists

- kugetsu-setup.md: Document multi-distro installation commands

skills/kugetsu/scripts/kugetsu-install.sh

@@ -38,6 +38,14 @@ add_to_shell "$HOME/.bashrc"
 add_to_shell "$HOME/.zshrc"
 
 echo ""
+echo "=== Verifying installation ==="
+if [ ! -f "$BIN_DIR/kugetsu" ]; then
+    echo "ERROR: kugetsu was not installed correctly."
+    exit 1
+fi
+echo "kugetsu installed at: $BIN_DIR/kugetsu"
+echo ""
+
 echo "Installation complete!"
 echo ""
 echo "Run this to start using kugetsu immediately:"