feat(CUB-28): [Extrudex] Define filament inventory database entities

Add storage_location and is_archived fields to Spool entity to complete
the filament inventory entity definition per CUB-28 requirements.

Changes:
- Spool entity: add IsArchived (bool, default false) and StorageLocation
  (nullable string, max 200) for physical inventory tracking
- SpoolConfiguration: add snake_case column mappings, defaults, and indexes
  (ix_spools_is_archived, ix_spools_active_archived composite)
- FilamentDtos: add IsArchived + StorageLocation to Response, Create, Update
- FilamentQueryDtos: add IncludeArchived and StorageLocation query filters
- FilamentsController: wire new fields into query, create, update, mapping
- FilamentValidators: add StorageLocation max-length validation

Build: PASS (0 errors)

backend/API/Controllers/FilamentsController.cs

@@ -46,9 +46,11 @@ public class FilamentsController : ControllerBase
         _logger.LogDebug(
             "Getting filaments: pageNumber={PageNumber}, pageSize={PageSize}, " +
             "materialBaseId={MaterialBaseId}, materialFinishId={MaterialFinishId}, " +
-            "materialModifierId={MaterialModifierId}, brand={Brand}, isActive={IsActive}",
+            "materialModifierId={MaterialModifierId}, brand={Brand}, isActive={IsActive}, " +
+            "includeArchived={IncludeArchived}, storageLocation={StorageLocation}",
             query.PageNumber, query.PageSize, query.MaterialBaseId,
-            query.MaterialFinishId, query.MaterialModifierId, query.Brand, query.IsActive);
+            query.MaterialFinishId, query.MaterialModifierId, query.Brand, query.IsActive,
+            query.IncludeArchived, query.StorageLocation);
 
         // Clamp pagination values
         var pageNumber = Math.Max(1, query.PageNumber);
@@ -77,6 +79,15 @@ public class FilamentsController : ControllerBase
         if (query.IsActive.HasValue)
             spoolQuery = spoolQuery.Where(s => s.IsActive == query.IsActive.Value);
 
+        // Exclude archived spools by default; include when explicitly requested
+        if (query.IncludeArchived != true)
+            spoolQuery = spoolQuery.Where(s => !s.IsArchived);
+
+        if (!string.IsNullOrWhiteSpace(query.StorageLocation))
+            spoolQuery = spoolQuery.Where(s =>
+                s.StorageLocation != null &&
+                s.StorageLocation.ToLower().Contains(query.StorageLocation.ToLower()));
+
         var totalCount = await spoolQuery.CountAsync();
 
         var items = await spoolQuery
@@ -185,7 +196,9 @@ public class FilamentsController : ControllerBase
             SpoolSerial = request.SpoolSerial,
             PurchasePrice = request.PurchasePrice,
             PurchaseDate = request.PurchaseDate,
-            IsActive = request.IsActive
+            IsActive = request.IsActive,
+            IsArchived = request.IsArchived,
+            StorageLocation = request.StorageLocation
         };
 
         _dbContext.Spools.Add(entity);
@@ -267,6 +280,8 @@ public class FilamentsController : ControllerBase
         entity.PurchasePrice = request.PurchasePrice;
         entity.PurchaseDate = request.PurchaseDate;
         entity.IsActive = request.IsActive;
+        entity.IsArchived = request.IsArchived;
+        entity.StorageLocation = request.StorageLocation;
 
         await _dbContext.SaveChangesAsync();
 
@@ -307,6 +322,8 @@ public class FilamentsController : ControllerBase
         PurchasePrice = s.PurchasePrice,
         PurchaseDate = s.PurchaseDate,
         IsActive = s.IsActive,
+        IsArchived = s.IsArchived,
+        StorageLocation = s.StorageLocation,
         CreatedAt = s.CreatedAt,
         UpdatedAt = s.UpdatedAt,
         QrCodeUrl = $"/api/qr/spool/{s.Id}"