Fix maintenance tasks showing wrong rod type for printer models (#351)

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.

backend/app/api/routes/maintenance.py

@@ -26,6 +26,7 @@ from backend.app.schemas.maintenance import (
     PrinterMaintenanceUpdate,
 )
 from backend.app.services.notification_service import notification_service
+from backend.app.utils.printer_models import get_rod_type
 
 logger = logging.getLogger(__name__)
 
@@ -33,12 +34,33 @@ router = APIRouter(prefix="/maintenance", tags=["maintenance"])
 
 # Default maintenance types
 DEFAULT_MAINTENANCE_TYPES = [
+    # Carbon rod models only (X1/P1/P2S)
     {
-        "name": "Lubricate Linear Rails",
-        "description": "Apply lubricant to linear rails and rods for smooth motion",
+        "name": "Lubricate Carbon Rods",
+        "description": "Apply lubricant to carbon rods for smooth motion",
         "default_interval_hours": 50.0,
         "icon": "Droplet",
     },
+    {
+        "name": "Clean Carbon Rods",
+        "description": "Wipe carbon rods with a dry cloth",
+        "default_interval_hours": 100.0,
+        "icon": "Sparkles",
+    },
+    # Linear rail models only (A1/H2)
+    {
+        "name": "Lubricate Linear Rails",
+        "description": "Apply lubricant to linear rails for smooth motion",
+        "default_interval_hours": 50.0,
+        "icon": "Droplet",
+    },
+    {
+        "name": "Clean Linear Rails",
+        "description": "Wipe linear rails with a dry cloth to remove dust and debris",
+        "default_interval_hours": 100.0,
+        "icon": "Sparkles",
+    },
+    # Universal (all models)
     {
         "name": "Clean Nozzle/Hotend",
         "description": "Clean nozzle exterior and perform cold pull if needed",
@@ -51,12 +73,6 @@ DEFAULT_MAINTENANCE_TYPES = [
         "default_interval_hours": 200.0,
         "icon": "Ruler",
     },
-    {
-        "name": "Clean Carbon Rods",
-        "description": "Wipe carbon rods with a dry cloth",
-        "default_interval_hours": 100.0,
-        "icon": "Sparkles",
-    },
     {
         "name": "Clean Build Plate",
         "description": "Deep clean build plate with IPA or soap",
@@ -71,6 +87,30 @@ DEFAULT_MAINTENANCE_TYPES = [
     },
 ]
 
+# System types that only apply to printers with a specific rod/rail type.
+# "carbon" = X1/P1/P2S series (carbon rods), "linear_rail" = A1/H2 series.
+# Types not listed here apply to all printers.
+_ROD_TYPE_REQUIREMENTS: dict[str, str] = {
+    "Lubricate Carbon Rods": "carbon",
+    "Clean Carbon Rods": "carbon",
+    "Lubricate Linear Rails": "linear_rail",
+    "Clean Linear Rails": "linear_rail",
+}
+
+
+def _should_apply_to_printer(type_name: str, printer_model: str | None) -> bool:
+    """Check if a system maintenance type should apply to a given printer model."""
+    rod_requirement = _ROD_TYPE_REQUIREMENTS.get(type_name)
+    if rod_requirement is None:
+        return True  # Not model-specific, applies to all
+
+    rod_type = get_rod_type(printer_model)
+    if rod_type is None:
+        # Unknown model — default to carbon rods (legacy behavior)
+        return rod_requirement == "carbon"
+
+    return rod_type == rod_requirement
+
 
 async def get_printer_total_hours(db: AsyncSession, printer_id: int) -> float:
     """Calculate total active hours for a printer from runtime counter plus offset.
@@ -94,13 +134,27 @@ async def get_printer_total_hours(db: AsyncSession, printer_id: int) -> float:
 
 
 async def ensure_default_types(db: AsyncSession) -> None:
-    """Ensure default maintenance types exist."""
-    result = await db.execute(select(MaintenanceType).where(MaintenanceType.is_system.is_(True)))
+    """Ensure default maintenance types exist, remove stale/duplicate ones."""
+    result = await db.execute(
+        select(MaintenanceType).where(MaintenanceType.is_system.is_(True)).order_by(MaintenanceType.id)
+    )
     existing = result.scalars().all()
-    existing_names = {t.name for t in existing}
 
+    default_names = {t["name"] for t in DEFAULT_MAINTENANCE_TYPES}
+
+    # Remove stale system types no longer in defaults (e.g. renamed types)
+    # and deduplicate: if concurrent requests created the same type twice,
+    # keep only the first (lowest id) and delete the rest.
+    seen_names: set[str] = set()
+    for t in existing:
+        if t.name not in default_names or t.name in seen_names:
+            await db.delete(t)
+        else:
+            seen_names.add(t.name)
+
+    # Create any missing default types
     for type_def in DEFAULT_MAINTENANCE_TYPES:
-        if type_def["name"] not in existing_names:
+        if type_def["name"] not in seen_names:
             new_type = MaintenanceType(
                 name=type_def["name"],
                 description=type_def["description"],
@@ -228,6 +282,11 @@ async def _get_printer_maintenance_internal(
     now = datetime.utcnow()
 
     for maint_type in all_types:
+        # Skip system types that don't apply to this printer model
+        # (e.g., "Clean Carbon Rods" for H2D which has steel rods)
+        if maint_type.is_system and not _should_apply_to_printer(maint_type.name, printer.model):
+            continue
+
         item = existing_items.get(maint_type.id)
         default_interval_type = getattr(maint_type, "interval_type", "hours") or "hours"