Add Formula Library ratings, Job Profitability report, and Quote Revision History improvements

- Formula Library ratings: thumbs up/down per company per formula; toggle on/off; sorts by net score; own formulas not rateable; FormulaLibraryRating entity + migration AddFormulaLibraryRatings
- Job Profitability report: actual labor cost (logged hours x StandardLaborRate) vs powder cost vs billed price per job; gross margin % color-coded; time-tracked-only filter; totals footer
- Quote Revision History: track Total price changes on every save; log Sent/Resent events with recipient email; replace flat table with grouped timeline UI (icons per event type, total-change badge on header)
- Setup Wizard: cap CompletedCount at TotalSteps so old 10-step data no longer shows 10/5
- Formula Library card: fix badge overflow on long titles; add Rate: label to make voting buttons discoverable
- Help docs and AI knowledge base updated for all three features

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

src/PowderCoating.Infrastructure/Repositories/UnitOfWork.cs

@@ -133,6 +133,7 @@ public class UnitOfWork : IUnitOfWork
     // Formula Community Library
     private IPlainRepository<FormulaLibraryItem>? _formulaLibrary;
     private IRepository<FormulaLibraryImport>? _formulaLibraryImports;
+    private IPlainRepository<FormulaLibraryRating>? _formulaLibraryRatings;
 
     // Purchase Orders
     private IPurchaseOrderRepository? _purchaseOrders;
@@ -488,6 +489,10 @@ public class UnitOfWork : IUnitOfWork
     public IRepository<FormulaLibraryImport> FormulaLibraryImports =>
         _formulaLibraryImports ??= new Repository<FormulaLibraryImport>(_context);
 
+    /// <summary>Repository for <see cref="FormulaLibraryRating"/> per-company thumbs votes; platform-level, no tenant filter.</summary>
+    public IPlainRepository<FormulaLibraryRating> FormulaLibraryRatings =>
+        _formulaLibraryRatings ??= new PlainRepository<FormulaLibraryRating>(_context);
+
     // Job Templates
     /// <summary>Repository for <see cref="JobTemplate"/> reusable job blueprints; tenant-filtered with soft delete.</summary>
     public IJobTemplateRepository JobTemplates =>