Add rework pricing type (Fixed vs Per-Item) and inline rework flow on Job Details

Adds a PricingType enum to ReworkRecord (FixedPrice | PerItem), surfaces the
choice in the rework modal on Job Details, and wires the resulting unit/total
price display. Includes migration AddReworkPricingType, updated repository
query for rework history, and help article updates.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Application/Mappings/JobProfile.cs

@@ -196,7 +196,9 @@ public class JobProfile : Profile
             .ForMember(dest => dest.JobItemDescription,
                       opt => opt.MapFrom(src => src.JobItem != null ? src.JobItem.Description : null))
             .ForMember(dest => dest.ReworkJobNumber,
-                      opt => opt.MapFrom(src => src.ReworkJob != null ? src.ReworkJob.JobNumber : null));
+                      opt => opt.MapFrom(src => src.ReworkJob != null ? src.ReworkJob.JobNumber : null))
+            .ForMember(dest => dest.ReworkPricingType,
+                      opt => opt.MapFrom(src => src.ReworkPricingType));
 
         // Job → JobDto (rework fields)
         // (IsReworkJob and OriginalJobId map by convention; OriginalJobNumber needs explicit map — handled in controller)