H2/A1 series have linear rails, not carbon rods. X1/P1/P2S have carbon
rods, not linear rails. Split rod-specific maintenance into model-aware
pairs: "Lubricate/Clean Carbon Rods" for X1/P1/P2S and "Lubricate/Clean
Linear Rails" for A1/H2. Added rod type classification to printer_models
and startup cleanup for stale/duplicate system maintenance types.