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.Core/Interfaces/IUnitOfWork.cs

@@ -161,6 +161,7 @@ IRepository<ReworkRecord> ReworkRecords { get; }
     // Formula Community Library
     IPlainRepository<FormulaLibraryItem> FormulaLibrary { get; }
     IRepository<FormulaLibraryImport> FormulaLibraryImports { get; }
+    IPlainRepository<FormulaLibraryRating> FormulaLibraryRatings { get; }
 
     // Employee Timeclock
     IRepository<EmployeeClockEntry> EmployeeClockEntries { get; }