Add Community Formula Library feature

Companies can now share their custom formula templates to a platform-wide
community library. Other tenants can browse, preview, and import formulas
as independent local copies. Includes attribution (source company name),
"Inspired by" lineage for re-contributed formulas, import counts, own-formula
badge, cascade diagram nullification, and AI assistant + help docs updates.

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

src/PowderCoating.Application/Mappings/FormulaLibraryProfile.cs

@@ -0,0 +1,35 @@
+using AutoMapper;
+using PowderCoating.Core.Entities;
+using PowderCoating.Application.DTOs.Company;
+
+namespace PowderCoating.Application.Mappings;
+
+public class FormulaLibraryProfile : Profile
+{
+    public FormulaLibraryProfile()
+    {
+        CreateMap<FormulaLibraryItem, FormulaLibraryCardDto>()
+            .ForMember(dest => dest.InspiredByName,
+                opt => opt.MapFrom(src => src.InspiredBy != null ? src.InspiredBy.Name : null))
+            .ForMember(dest => dest.InspiredByCompanyName,
+                opt => opt.MapFrom(src => src.InspiredBy != null ? src.InspiredBy.SourceCompanyName : null))
+            .ForMember(dest => dest.AlreadyImported, opt => opt.Ignore()); // set by service
+
+        CreateMap<FormulaLibraryItem, FormulaLibraryDetailDto>()
+            .IncludeBase<FormulaLibraryItem, FormulaLibraryCardDto>()
+            .ForMember(dest => dest.FieldCount,
+                opt => opt.MapFrom(src => CountFields(src.FieldsJson)));
+    }
+
+    private static int CountFields(string fieldsJson)
+    {
+        try
+        {
+            var doc = System.Text.Json.JsonDocument.Parse(fieldsJson);
+            return doc.RootElement.ValueKind == System.Text.Json.JsonValueKind.Array
+                ? doc.RootElement.GetArrayLength()
+                : 0;
+        }
+        catch { return 0; }
+    }
+}