Add maintenance documentation links with model-specific wiki URLs (#59)

Features:
  - Add wiki_url field to MaintenanceType for custom type documentation links
  - Add printer_model to MaintenanceStatus for model-specific URL mapping
  - Display external link icon next to maintenance item names
  - Map system maintenance types to Bambu Lab wiki pages by printer model:
    - Lubricate Linear Rails, Clean Nozzle/Hotend, Check Belt Tension
    - Clean Carbon Rods (X1/P1 only), Clean Build Plate, Check PTFE Tube
    - HEPA/Carbon Filter, Left Nozzle Rail (H2 series)
  - Add Documentation Link input to custom type create/edit forms

  Bug fix:
  - Fix 500 error when assigning maintenance type to printer (lazy loading)

  Database:
  - Add migration for wiki_url column on maintenance_types table

backend/app/api/routes/maintenance.py

@@ -294,9 +294,11 @@ async def _get_printer_maintenance_internal(
                 id=item_id,
                 printer_id=printer_id,
                 printer_name=printer.name,
+                printer_model=printer.model,
                 maintenance_type_id=maint_type.id,
                 maintenance_type_name=maint_type.name,
                 maintenance_type_icon=maint_type.icon,
+                maintenance_type_wiki_url=getattr(maint_type, "wiki_url", None),
                 enabled=enabled,
                 interval_hours=interval,
                 interval_type=interval_type,
@@ -317,6 +319,7 @@ async def _get_printer_maintenance_internal(
     return PrinterMaintenanceOverview(
         printer_id=printer_id,
         printer_name=printer.name,
+        printer_model=printer.model,
         total_print_hours=total_hours,
         maintenance_items=maintenance_items,
         due_count=due_count,
@@ -417,7 +420,16 @@ async def assign_maintenance_type(
     )
     db.add(item)
     await db.commit()
-    await db.refresh(item)
+
+    # Re-fetch with relationship loaded for response serialization
+    from sqlalchemy.orm import selectinload
+
+    result = await db.execute(
+        select(PrinterMaintenance)
+        .options(selectinload(PrinterMaintenance.maintenance_type))
+        .where(PrinterMaintenance.id == item.id)
+    )
+    item = result.scalar_one()
 
     return item
 
@@ -494,9 +506,11 @@ async def perform_maintenance(
         id=item.id,
         printer_id=item.printer_id,
         printer_name=printer.name,
+        printer_model=printer.model,
         maintenance_type_id=item.maintenance_type_id,
         maintenance_type_name=item.maintenance_type.name,
         maintenance_type_icon=item.maintenance_type.icon,
+        maintenance_type_wiki_url=getattr(item.maintenance_type, "wiki_url", None),
         enabled=item.enabled,
         interval_hours=interval,
         interval_type=interval_type,

backend/app/core/database.py

@@ -387,6 +387,12 @@ async def run_migrations(conn):
     except Exception:
         pass
 
+    # Migration: Add wiki_url column to maintenance_types for documentation links
+    try:
+        await conn.execute(text("ALTER TABLE maintenance_types ADD COLUMN wiki_url VARCHAR(500)"))
+    except Exception:
+        pass
+
 
 async def seed_notification_templates():
     """Seed default notification templates if they don't exist."""

backend/app/models/maintenance.py

@@ -20,6 +20,7 @@ class MaintenanceType(Base):
     # Interval type: "hours" (print hours) or "days" (calendar days)
     interval_type: Mapped[str] = mapped_column(String(20), default="hours")
     icon: Mapped[str | None] = mapped_column(String(50))  # Icon name for UI
+    wiki_url: Mapped[str | None] = mapped_column(String(500))  # Documentation link
     is_system: Mapped[bool] = mapped_column(Boolean, default=False)  # Pre-defined vs custom
     created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
 

backend/app/schemas/maintenance.py

@@ -13,6 +13,7 @@ class MaintenanceTypeBase(BaseModel):
     # "hours" = print hours, "days" = calendar days
     interval_type: str = Field(default="hours", pattern="^(hours|days)$")
     icon: str | None = None
+    wiki_url: str | None = None  # Documentation link for custom types
 
 
 class MaintenanceTypeCreate(MaintenanceTypeBase):
@@ -25,6 +26,7 @@ class MaintenanceTypeUpdate(BaseModel):
     default_interval_hours: float | None = Field(default=None, ge=1.0)
     interval_type: str | None = Field(default=None, pattern="^(hours|days)$")
     icon: str | None = None
+    wiki_url: str | None = None
 
 
 class MaintenanceTypeResponse(MaintenanceTypeBase):
@@ -96,9 +98,11 @@ class MaintenanceStatus(BaseModel):
     id: int
     printer_id: int
     printer_name: str
+    printer_model: str | None  # For model-specific documentation links
     maintenance_type_id: int
     maintenance_type_name: str
     maintenance_type_icon: str | None
+    maintenance_type_wiki_url: str | None  # Custom wiki URL for the type
     enabled: bool
     # Interval configuration
     interval_hours: float  # custom or default (hours for print-based, days for time-based)
@@ -121,6 +125,7 @@ class PrinterMaintenanceOverview(BaseModel):
 
     printer_id: int
     printer_name: str
+    printer_model: str | None  # For model-specific documentation links
     total_print_hours: float
     maintenance_items: list[MaintenanceStatus]
     due_count: int